Drags WaterCooling Project!

[dragflameson]

Alright, time to do this finally. I just got this case to water cool with, the RAIDMAX Silver Case - Model# ATX-268WSP. I've been wanting to do this for a long time now, so it's time to go all out and do it already! At the same time I figured I would keep a little "journal" here so you all could follow it, give me other ideas, or help! ;)

http://images10.newegg.com/productimage/11-156-019-12.JPG

I like it a lot because it has 4 x 80mm intakes in the front, 2 x 80mm intakes in the side with a window, and then I'm going to cut a 120mm blow hole in the top of it between the PSU and 5.25" bays. There is only a 60mm fan spot in the back, which kind of stinks, but I could probably do something with that - at least turn it into a 80mm exhaust hole hopefully!

I'm going to cut out the bottom 3.5" bays, leaving only the top 5.25" bays and the top two 3.5" bays, which will leave the whole bottom open where there are the 4 80mm intakes.

http://images10.newegg.com/productimage/11-156-019-09.JPG

I'm going to fill that whole bottom up with some kind of rads. I would like a dual 120mm rad, if it wont fit then I'll probably have to live with two 80mm rads.. unless there is something else.

Anyways, I'll post some pictures as soon as I start modding it with the new 120mm blow hole and cutting all those bottom 3.5" bays out and lastly doing something with that 60mm exhaust in the back. This is gonna be sick!

:t

[Happy Joe]

Go to Autozone or your local parts store and measure a 1977 pontiac bonneville heatercore. 2 120mm fans will fit on it very nicely you just have to see if it will fit your case. If you can find a copper one, snag it. Should run you about 20 bucks.
Enjoy!
PS if youre going wet , why add so many fans?

[dragflameson]

I actually don’t think I have a chance of fitting two 120mm fans on top of each other standing up without loosing both my floppy and hdd cages - something I'm not going to take out! And it definitely wouldn’t fit laying down of course.

I'm probably going to have to go with two 80mm rads side by side on the bottom with the two 80mm intakes and then I'll just put two 80mm fans on the top two 80mm case intakes for extra air flow inside the case.

I was thinking something like this (http://www.frozencpu.com/images/products/detail_hires/ex-rad-25.jpg) should work, but they don’t give the dimensions! I want to make sure it wouldn’t cover up the other two 80mm intakes above it if I laid it down with the bottom two 80mm intakes. I will probably get that with the 1/2" fittings if it where to fit my case, unless there is something else I don’t know about.

Sound okay?

[Happy Joe]

I believe that this may help;
http://www.dangerden.com/mall2/more_1pics.asp?fmmore=230
dims at bottom.
It looks ok but I worry that it may not be extreme enough, for you, in the long run.
It certainly looks better that the radiators that I played with a couple of years ago.
Enjoy!
(edit) lots of good info and case gallery here:
http://www.xtremesystems.org/forums/forumdisplay.php?s=&forumid=70

[dragflameson]

This is what I'll be using (so far) for my setup:

-------------------------------------
Radiator:

https://www.dangerden.com/images/heater_core/heater_core_small.gif

DangerDen Heater Core
Specs: Outside: 6 1/8" x 7 3/8" x 2"
With 1/2" Barbs

-------------------------------------
Fan Shroud:

http://www.dtekcustoms.com/ProductImages/radiators/Shroud%20kit.jpg

D-Tek Core Fan Shroud Kit
Specs: 1 3/8" X 6" x 5 7/8"

-------------------------------------
Fan for the Heater Core:

http://www.crazypc.com/images/fans/ystech120full.jpg

YS Tech 120x38mm
Specs: 3pin - 125.5CFM - 45dBA

-------------------------------------
Fan for the Blow Hole:

http://www.crazypc.com/images/fans/crystal/4blueledfanfull.jpg

LED Blue 120x25mm
Specs: 3pin - 69CFM - 4 LEDs

-------------------------------------
Other:

3 to 4 PIN with RPM Sensor Wire Adapter
I rather not run the YS Tech off the motherboard.

-------------------------------------

And this is how it will be mounted to the front of my case:

http://www.dtekcustoms.com/ProductImages/radiators/radiator_assembly.JPG

This is all I'm going to do for now. Once it all comes in I'll drill out the 120mm fan spots and get everything mounted and take it from there!

[dragflameson]

Welp, just placed my 2nd order, this time with FrozenCPU.

-------------------------------------
Pump:

http://www.frozencpu.com/images/products/detail_hires/ex-pmp-22.jpg

Swiftech MCP650™ 12v Water Pump
Specs: 317 GPH (1200 LPH)
Maximum Head: 10 ft (3.1 m)

-------------------------------------
Reservoir:

http://www.frozencpu.com/images/products/detail_hires/ex-res-39.jpg

Green UV Reactive Tundra
Specs: Single 5.25" Bay Reservoir

-------------------------------------
Tubing:

http://www.frozencpu.com/images/products/detail_hires/ex-tub-29.jpg

Tygon Anti-Kink
Specs: 1/2" ID (5/8" OD) - 7ft.

-------------------------------------
Coolant:

http://www.frozencpu.com/images/products/detail_hires/ex-liq-02.jpg

http://www.frozencpu.com/images/products/detail_secondary/ex-liq-02_3.jpg

Swiftech HydrX Coolant
Specs: Green UV Reactive

-------------------------------------

And that's all again for right now. There's still a few more things I need to pick up, but I will have some pictures of the case soon enough!! Still planning it all out a bit before I go and do it, but I'm about to start cutting it up tomorrow!!

[Xe']

Dragflameson,
I have never done a water cooled system myself, but is there a specific reason why you are pulling air through your radiator (making it warmer air) into your case. I would have through that it would be better to push air from your case out through the radiator. Are you doing it this way because it just works best for your setup, or am I just missing something?

[dragflameson]

Xe' this is my 1st time doing this, I've never done it either.

I've been doing a lot of reading on it all and the way I will be mounting the heater core is most popular.

You would think that it makes sense to have the rad fan push air from inside the case out the front of the case through the rad.

I look at it kind of like a loose/loose situation.

If you mount it so that cool air is being sucked in through the rad:
-You're getting the coldest of air being passed through the rad - Good.
-You're bringing in a lot of warm air inside the case. All that cool air coming through the front and through the rad is all turning to warm air and ending up inside the case - Not so Good.

If you mount it so that case air is being blown out the front through the rad:
-You're ambient air temp inside the case surrounding every tube and component is going to be generally cooler than the above method - Good.
-The air being blown through the rad from inside the case probably isnt going to be as cool as any air coming directly from the outside, so that wouldn’t be as good as the above method - Not so Good.

All I know is the way I'm doing it is done by almost all W/C'ers who mount their rad in the inside front of their case like I am... I guess that’s why every single one of them at least has a 120mm blow hole for exhaust!

[dragflameson]

Here are some of the first case mods to be done:

http://pages.cthome.net/dragfameson/WaterCooled/casemod001.jpg

The 120mm fan nicely cut into the top of the case as a blow hole which should work out really nice. I didn’t have room to squeeze this fan in-between the CDROM drive and PSU, since my new PSU is longer than my old one. It's no big deal though, I'm just going to put the CDROM drive in the 2nd bay down from the top and then use that top bay for my fan controller.

http://pages.cthome.net/dragfameson/WaterCooled/casemod002.jpg

Here is the bottom section of the case cut out for the heater core to fit in. It should fit nicely on it's side laying down with the barbs on the close end. As soon as it comes in I will cut out most of the front to match up with the heater core and then mount it. Hopefully it all goes as planned!

:t

[dragflameson]

Here's the front of my case all done now. Drilled in 70 holes almost perfectly to help more air get into the heater core. Hopefully it makes a big of a difference as the time it was worth. Also you may have noticed I painted the inside of it blue. It's looks pretty cool like that. I did it just because ;)
I'm going to paint the inside of the case that same color as well. And I need to find a cool case badge to put on there!

Anyways, hope you like:

http://pages.cthome.net/dragfameson/WaterCooled/casemod003.jpg

[dragflameson]

Finished up the last few case mods just now. Opened up the one 60mm hole in the back, and at the same time cut in a 2nd 60mm hole just for that extra amount of exhaust. I know it's not a lot, but it cant hurt... right?!

Back of case - Before:

http://pages.cthome.net/dragfameson/WaterCooled/case_back_stock.jpg

Back of case - After:

http://pages.cthome.net/dragfameson/WaterCooled/casemod004.jpg

Yes, the holes arent perfect, but its going to get the job done... thats all that really matters. It was a hard spot to get at. And anyways... it's the back side of the case - who's going to see it??

Front of case - Heater core spot cut open:

http://pages.cthome.net/dragfameson/WaterCooled/casemod005.jpg

Getting closer now finally! :D

[dragflameson]

Here she is, all primed up! ;)

I used "Rust-Oleum's" Painter's Touch Wet or Dry Sandable Primer.

http://pages.cthome.net/dragfameson/WaterCooled/casemod006.jpg

Probably going to start painting it in a few hours. I'll let it sit out in the sun and dry up good for a while :D

[Johnny Fist]

Those holes in the back of the case are going to come back and bite you in the behind when the project is finished. You watch, you'll be sitting there looking at the front and how nice it looks and all you'll be able to think about is how bad those two holes came out.

[crossedup]

Best way I have found to make holes round manually is to use the cutting disc on the dremel and just put it in the hole and use the edge, its already round anyway.

What size cutting disc depends on the hole. You can use the biggest one. :D

By what size, I mean i save the ones that are worn down a little so I have more than 1 diameter to choose from. Comes in handy. Ive got nice round holes for light switches and such that way.

Ya ya, could use a drill for smaller holes. Wheres the fun in that. :D

[Johnny Fist]

Do you have access to an air compressor and air powered tools or are you limited to a dremel? If you can get a right angle die grinder hooked up to an air compressor I could show you a trick or two to get those holes round, or rounder anyway.

[dragflameson]

Originally posted by Johnny Fist
Those holes in the back of the case are going to come back and bite you in the behind when the project is finished. You watch, you'll be sitting there looking at the front and how nice it looks and all you'll be able to think about is how bad those two holes came out. Nope, actually not ;)
Looks like perfectly mounted fans like thats the way it was made :D

http://pages.cthome.net/dragfameson/WaterCooled/watercooled001.jpg

So I think it's coming along very well.. I just hope to God it all works! I just keep getting this feeling the whole case is just going to fall apart and it's going to be some kind of disaster :(

Oh yeah... like the paint job? It's done now!

[Johnny Fist]

Thats a beautiful paint job.

[fishybawb]

That's looking sweet drag :cool: I wish I had the time, motivation and ability with power tools to do something like that :D

[crossedup]

Do you have access to an air compressor and air powered tools or are you limited to a dremel?

Got an air compresser right next to my bench, use it mostly for blowing out fans and PSU's, that sort of thing.

What would you recommend?

Nice paint job too, BTW.

[dragflameson]

Thanks everyone, I'm really glad you all like it so far!

I'm just waiting for the last parts to come in and then I'll be ready to hook it all up.

-------------------------------------
CPU Block:

http://cooltechnica.com/Merchant2/graphics/00000001/MCW6000-A-installed-250.gif

Swiftech MCW6002-A
Specs: 1/2" Barbs
CPU Water Block for AMD Socket A

-------------------------------------
Side Door Fan:

http://www.frozencpu.com/images/products/detail/fan-70.jpg

80mm Green Fan UV Cold Cathode Fan
Specs: 32.5 CFM, 2700 RPM, 28.3 dBA

-------------------------------------
RAM Fans:

http://www.crazypc.com/images/fans/delta60mmfull.jpg

Delta 60mm Fan
Specs: 60x25mm, 3pin, 38cfm, 6800rpm, 46.5dBA
To active cool my RAM, I also have two being used
as exhaust fans on the back.

-------------------------------------
Fan Grill:

http://www.crazypc.com/images/casemods/guards/skulltooth/skulltoothfull.jpg

Long Tooth Skull
Specs:80mm Fan Cover for the Side Door Fan

-------------------------------------
So that should be all I need. I also got some more 3 to 4 pin adapters, because I'm going to need more of those, but other than that I think that's everything to complete the project. Oh yeah, I got 8 hose clamps from Home Depot as well, to secure the tubes ;)

[genesound]

You can always cut some better holes in a piece of sheet metal and pop rivet it right over the existing piece, if you decide to later... it might add some rigidity too ;)

Lookin good drag :t

[dragflameson]

Originally posted by genesound
You can always cut some better holes in a piece of sheet metal and pop rivet it right over the existing piece, if you decide to later... it might add some rigidity too ;) Yeah, if we thought of doing that at the time I probably would have, good idea!

Oh well... its all good though. The two 60mm fans right next to each other, and then the motherboards I/O protective back pannel strengthened it right up nicley :D

[CompGeek01]

Two thumbs up here! Nice job with it so far!!!!

[crossedup]

Where did you find that fan grill? Thats pretty sweet, I need a few of those.

[dragflameson]

Originally posted by CompGeek01
Two thumbs up here! Nice job with it so far!!!! Thanks :)

crossedup - found those at crazypc.com, they got others just like it :)

[dragflameson]

Here is the latest progress, I'm just waiting for my res to come in, once it does I'll be good to go! Should be some time early this coming week :D

http://pages.cthome.net/dragfameson/WaterCooled/watercooled002.jpg

[fizur2002]

Mad props to you m8. Keep up the good work. I cant wait to get started on my project, but its going to be a while before i really get a change to work on it.

[dragflameson]

Thanks. That was the same with me, I've wanted to do this for so long now! Finally making it happen :D

[DozerLYP]

nice rig dude.

where did you get that Long Tooth Skull fan grill. it kick's a**...

[dragflameson]

Originally posted by DozerLYP
nice rig dude.

where did you get that Long Tooth Skull fan grill. it kick's a**... Thanks, I got it at crazypc.com, they had a few more. It just came in the other day, looks real nice in person!

Anyways, I'm about to finish this project up. It should be running by sometime tomorrow finally :D

[dragflameson]

Finally, I had it all setup and running, but then ran into a very unfortunate problem.

I bleed the whole system and it was running fine except for the one last tube in the loop coming straight from the CPU block outlet into the back of the pump. The suck from the pump was just too strong for the thickness of the tube and was creating a vacuum which was almost sucking the tube totally flat :mad:

http://pages.cthome.net/dragfameson/WaterCooled/problem001.jpg

As you can see that tube all the way on the left was the one that was getting sucked flat. All the others to the right were the way it was supposed to be.

There was nothing I could do besides drain the whole system, take it all apart and then re-run all the tubing in the whole loop in a different order :(

What I ended up having to do was take the pump out and mount it in the opposite direction and have it suck from the heater core where there would be a greater flow coming out from behind it, thus having to drill two more hole and all those wonderful things just to turn the pump around :rolleyes:

Now I don’t have any room for the fans in the side of the case either... so that nice little fan guard I got there isn’t even going to be used, or that UV 80mm fan :( Oh well.

[fizur2002]

That sucks dude, that grill was nice too. Hope you get it up and running. GL

[dragflameson]

Thanks, things are getting pretty crazy right now, having all sorts of little problems thats just turning into one big mess it feels like, but it will run... I hope :)

[Happy Joe]

There is a version of tygon tubing that has a wire reinforcement that is inside the plastic . I have used it on aplications which would colapse ordinary tygon tubing. check out your local hardware stores. (if you use it be sure to seal the exposed wire at the ends with clear siilicone to prevent rust).
I have also used stainless steel spring stock inside the tube to prevent colapsing but it is quite expensive and very hard to find.
Good luck!
Enjoy!

[dragflameson]

Hey, those are some good ideas, thanks man :D

I turned the pump around and have it sucking from the rad. The tube from the back side of the pump to the rad is very short and it still is colapsing, but its bearley noticable, I dont think its making any difference.... its much better than that other tube was in the picture :)

[fizur2002]

get something that you can turn down the voltage on your pump, cuz if you do that, it should lessen the power of the pump and get rid of your colapsing problem.

[dragflameson]

Yeah, that is what I 1st thought of, but then didnt think that would be the best solution, so I turned the pump around so that last tube in the loop would be very short.

Now it's connected right to the heater core and the tube is very short. The pump is just bearley making that last tube colapse now and if I wasnt just sitting there staring at it today I wouldnt of even noticed it. I dont think its going to have an affect on the performance of the system since its so minute ;) Wrong?

[fizur2002]

What i would think would be best would be to have the coolest water going to your CPU block first and then to the rest of the system. So if that is the way you have it, the keep it that way. IMO

[dragflameson]

Yeah, I thought the same at first too.

I was so worried about having the block be directly after the heater core to get the best performance (coolest water to the CPU), but my loop would have been so long and twisted if I ran it that way.

I did a lot of reading on the subject because of this and found that the truth is no matter which way you run it the difference is going to be of less than 1 degree. And you're better off running it the shortest and easiest way you can, which makes sense to me now after trying to run it so that the block was right after the heater core. I switched it around now ;)

The difference it makes is too little to worry about.

UPDATE: When I had to re-run the loop I couldn’t exactly drain the whole system, but really had to redo it no matter what. So I tried without draining it... that didn’t go so well. Water just came poring out of everywhere at once and it was impossible to control, some may have splashed on the motherboard and got it wet... now it doesn’t seem to be running right. There is this special cleaning method I have to try to get it working again (if it got wet), if not then I might have to get a new one.

[fizur2002]

Just a little tip, if you get your electronics get wet by something other than isoprople alcohol, you can usually let it dry for about an hour to make sure its dry, and then its usually safe to turn it back on again without any problems.

[dragflameson]

Yeah, there's this hot water wash method where you use hot distilled water and spray the whole board down with it and then dump a couple bottles of the isopropyl alcohol all over it then you put it in the oven for 2 hours at 150F. I've read a lot about this; people have been pretty successful doing it this way :)

[fizur2002]

i wouldnt trust the oven bit, i would just let it air dry. IMO

[Happy Joe]

I have had very good results just letting it dry for a couple of hours with a fan on it. If it has any chance of still being wet I would not power it up. This is where distilled water has a real advantage. If it is fresh (has a very low ionic contamination level), it is actually a pretty good insulator.
Blow dryers also work well. I once bought a circuit board scrubber that had a dryer that was, basicly, a 5 horsepower motor hooked to a Paxton supercharger and heater elements that used several thousand watts, boards came out bone dry. Kinda overkill for home use though.
Enjoy!
(edit) the hot DI wash you mentioned followed by a bake should work just fine. Just watch the heat.

[crossedup]

Ive always thrown them in the back seat of my blazer ( well, set them ) and gone to work and left them in the truck with the windows rolled up out of direct sunlight ( the board ) for a 9 hour or so shift.

Always good and dry.

Im serious. My father and I recycle computers, they get collected in outside bins, subject to the whims of Mother Nature. they come in wet ALOT.

Ive always had good success with that method. If they are real soaked I give them a couple days standing on end. Not as hot as an oven in there but hot enough and very dry.

[dragflameson]

Well its good to hear more people with success stories doing these types of methods! :D

I'll post some pictures of the final project once it's finally running again! :t

I just ordered some UV Reactive Round IDE cables to add some more color and keep my wire management going good at the same time :)

[dragflameson]

I started this project one month ago tomorrow and FINALLY it's up and RUNNING! Putting WinXP Pro on it right now as we speak :D

Here is the picture I took right before I plugged everything in and turned it on. I was so nervous something was going to go wrong or it just wasn’t going to turn on or something lmao, but it did, and it did very nicely, as you can see in the 2nd & 3rd pictures.

http://pages.cthome.net/dragfameson/WaterCooled/watercooled003.jpg

Finally running! It's going to look awesome in the dark tonight! I CANT wait!!!

http://pages.cthome.net/dragfameson/WaterCooled/watercooled004.jpg

As you can see on my monitor I'm in the BIOS. The system Temp was 26C and the CPU Temp was 24C - How awesome is that?!?!?! :D

http://pages.cthome.net/dragfameson/WaterCooled/watercooled005.jpg

Now its getting everything installed, setup & updated for the rest of the night hehe

[Strawbs]

Congrats Drag! great job - I might have chosen a more vibrant case colour scheme myself, but the build is spot on.

;)

[Magua]

Nice looking rig, congrats

[dragflameson]

Thank you :)

Strawbs, I did think about going a little more crazy with it, like maybe blue with yellow or green or some other 2nd color, but I decided not to. I've never done it before and didnt want it to come out tacky looking :)

[dragflameson]

Here's some cool pictures of it @ night :)

http://pages.cthome.net/dragfameson/WaterCooled/watercooled006.jpg

http://pages.cthome.net/dragfameson/WaterCooled/watercooled007.jpg

http://pages.cthome.net/dragfameson/WaterCooled/watercooled008.jpg

I like.

[zacker]

WOW! Drags, that is looking waaayyyy cool! Like what ya did with the rad. Works the same as a car right? the cooler water (which is cooled in the rad by the air flow passing throught the rad) circulates around the inside if the box? One question..... on a car, the water actually passes through the engin ... hows it work in the comp.?? Im thinking that a freon or refrigerant 12 type system to "air condition" the computer would work better... anyone ever try it?? Ahhhhh, Im too old to worry about it now anyway!....lol
Later.
Oh yeah, I'll be needing help with the web site soon... I'll call ya!
-zacker-

[dragflameson]

LOL That^^ would be my uncle, and yeah - you know how it works! ;)

[cheeseman]

that case "pretty":-@

[dragflameson]

Thanks cheese :)

Some of you might be wondering what exactly this w/c system is actually cooling, so I figured I should post the system specs...

Motherboard: EPoX EP-8RDA3+ rev3.2 mosfet & pll sinked w/ Thermalright NB-1C
Memory: OCZ EB Series Platinum Edition 1GB (2x512MB Dual) PC-3500
CPU: AMD Mobile Athlon XP2600 Processor (IQYFA: 0350 MPMW)
GPU: eVGA GeForce FX 5700 Ultra 128MB Graphics Card
PSU: Fortron 530W PSU w/ UV Reactive sleeves & connectors

I will also post the overclock results as soon as I find my max stable o/c

:t

[Happy Joe]

Good job! looks great!!
Enjoy!

[dragflameson]

Originally posted by Happy Joe
Good job! looks great!!
Enjoy! Thanks man.

You going to go back to w/c ever HJ??

[The Lodge]

That's hot drag. Very nice work. I'll ask you for some tips if I ever decide to get "wet". How are those fans attached to your ram? :D :t

[dragflameson]

Originally posted by The Lodge
That's hot drag. Actually its "cool" lol ;) j/k :D LOL I know what you ment of course haha

Originally posted by The Lodge
I'll ask you for some tips if I ever decide to get "wet". How are those fans attached to your ram? :D :t Thanks :) Velcro my friend... works great! Those fans will never fall off by themselves!

[cheeseman]

if you build enougth of those you don't need house lamps :D :D just use the cool computers

[dragflameson]

Hehe, they're not that bright! :)

Lodge, clean up your PM inbox a little bit, its full :p

[The Lodge]

Originally posted by dragflameson
Lodge, clean up your PM inbox a little bit, its full :p How’d you know? I’ve never cleaned it out before, so there were messages from September of last year. Now it’s clean though.

Edit: Found out how, just got the email telling me what’s up.

[dragflameson]

Originally posted by The Lodge
Edit: Found out how, just got the email telling me what’s up. So then you got my PM?? I was just about to try to send it again :)

[cheeseburgerman]

how pretty

[dragflameson]

Just got prettier too lol... Got the overclock up to 2.75GHz right now thats 16 hours Prime STABLE :D

[widget2003]

Originally posted by dragflameson
Just got prettier too lol... Got the overclock up to 2.75GHz right now thats 16 hours Prime STABLE :D

lol that can't handle Prime at that speed for any more then 20 minutes, lol thats right i read your other post :D

[The Lodge]

Originally posted by dragflameson
So then you got my PM?? I was just about to try to send it again :) Nope. Just got an email telling me my inbox was full.

[dragflameson]

Originally posted by widget2003
lol that can't handle Prime at that speed for any more then 20 minutes, lol thats right i read your other post :D No.. it def. ran Prime for 16 Hours - no lies. But I think that Prime "session" killed my system because yeah... now its very unstable lol.

[fizur2002]

so why dont you bump it back down to 2.4ghz and then do a sis sandra cpu burn for a couple days to see if its stable? then you can go back up from there.

[dragflameson]

fizur2002, because I know the chip is damaged now :( and I got three others to fool with... one of these has to be the lucky one!

It is actually very hard to hit 2.8GHz on plain water with a setup like mine. Ive been doing a lot of reading and research, there seems to be almost a standard with these chips:

Got water - you should be able to hit 2.7GHz - 2.8GHz
Got water cooled TEC - you should be able to hit 2.8GHz - 2.9GHz
Got vapo chill - you should be able to hit 2.9GHz - 3GHz at least

I've seen most people with vapo running 3.1GHz with only 2.0Vcore, and I was talking to a new friend on MSN who is running 3.2GHz with proof at 2.1Vcore.