AMD K6-2 and FIC VA-503+

[Shelomo]

I'd like some advice about overclocking an AMD k6-2 333 on a FIC VA-503+ motherboard. The downside is that I have 4 sticks of EDO SIMM's, 32 megs each. With the 66Mhz bus and a 5.5 multiplier, it's running fine at 366 now, but I've read that with this chipset (MVP3) that I *should* be able to go to a 75-95 Mhz bus, but I haven't been able to do it, although I did get it to POST at 75Mhz with 5x, but I decided to experiment with other things rather than thoroughly test this setting. If anyone's familiar with this stuff and can help me get my memory/CPU on a higher bus, please tell me.

[This message has been edited by Shelomo (edited 02-11-99).]

[Aris]

There should be 2 settings, 1 for memory speed, 1 for Front Side Bus (FSB) speed. You should be able to run the FSB as high as the processor will take it, and leave the memory bus at 66MHz. Check Anands web site as well as www.tccomputers.com in their tech info area.

[CMonster]

I believe on the 503+ the SIMMs are supposed to run asyncronous automattically - so there are no memory jumper settings for SIMMs, and no adjustments in BIOS should be necessary. When you upgrade to DIMMs then there are PC-100 and Non-PC 100 jumpersettings, as well as effective timing adjustments in BIOS. Remember that the 100mhz FSB (front side bus) is exactly that; and since you are using SIMMs instead of PC-100 SDRAM DIMMs about all you are speeding up at the moment is your 1MB of L2 cache and the base frequency of the CPU.

I do not know what your chip is capable of doing, but you could easily attain 350 on a 100mhz bus (Jumper settings are in your manual) and your overall system performance is likely to be better than 366 on a 66 mhz bus.

Probably that chip will do 380 @4x95 and 2.4 volts if you have good cooling.

The settings for 95mhz bus are:
CLK1:2-3/CLK2:1-2/CLK3:2-3

[This message has been edited by CMonster (edited 02-11-99).]

[Shelomo]

Actually, I've done some more research and asked a friend of mine who helped me put this system together in the first place, and am right now posting the workiing response to my own question, in case anyone else has this problem.
Don't ask me why, but the motherboard manual lists asynchronous memory settings in the DIMM settings. Although it says DIMM, the settings are the same if you're using SIMMs.

So to get a 95 Mhz FSB and 66Mhz memory bus, you set these jumpers :
SDRAM 1: 1-2
SDRAM 2: 1-2
SDRAM 3: 2-3

CLK 4: 2-3

Then follow the manual for the External Bus and multipliers.

Again, I know it says SDRAM, but it affects SIMM timing also. I'm thinking they couldn't fit SIMM/SDRAM in the space for the jumper labels or something. What these jumper settings will do is give you a 2/3 memory bus/FSB ratio, so if you run a 100 Mhz FSB, your memory will be at 66 Mhz. Right now I have 4x95Mhz @ 2.3 volts and all is well.

[This message has been edited by Shelomo (edited 02-11-99).]

[This message has been edited by Shelomo (edited 02-11-99).]

[CMonster]

Interesting? I have run my 60ns EDO SIMMs in my 503+ at 100mhz FSB without changing the SDRAM timing from PC-100 without a problem whatsoever. My conclusion with regard to those results and the way the manual reads is that the SDRAM timing did not affect the timing of the SIMMs - perhaps I just have some incredible EDO SIMMs - nah.

George

[bighammer]

Cmonster{as in COOKIE?}
alot of EDO 60ns will do the 100 and sometimes up to 112.
have fun

[Shelomo]

Hmmmmmmmm... Well memory is a really picky thing, and I've heard stories of certain sticks of 10ns SDRAM not working on a 100Mhz bus, even though it should. I'm guessing that my memory just doesn't like going over 75 Mhz. I *know* that the SDRAM timing jumpers affect the SIMM timing, because I could never get the thing to POST at 95 Mhz until I changed the SDRAM jumpers to a 2/3 ratio, and I don't have SDRAM! Nothing else changed, and I know my old, way obsolete memory is the weak link here. Right now, I'm trying to find a voltage/cooling balance to see if I can push the CPU up to 400Mhz. Anyone know any good deals on SDRAM?

[CMonster]

CMonster yeah, as in COOKIE hehe...

Well I guess "Non-PC100" means EDO SIMMs as well then, although that is certainly not specified in the manual. Thanks for the information..I will have to check into it further one day - right now I have the 8ns SDRAMS in there so I have no reason to put the EDO back in.

If it's of any interest to you I could never get my FIC boards to run stable on 75mhz bus until I set back to PIO mode 4 on my Samsung UDMA drives - no problems at all with 90, or 95, and 100mhz bus on either of my 503+ boards (I have the last two revisions). Funny thing was that I had no problems whatsoever running the exact same hardware on my Shuttle 569 using the 75mhz bus.

As for my 60ns EDO SIMMs being able to run on a 100mhz bus I have doubts about that being possible - it was just generic junk on sale for cheap; I must have been extreamly lucky. I tried the SDRAM settings both ways with the EDO in there and it did not seem to make any difference.

I did have to set the SDRAM to non-PC100 (while using PC-100 DIMMs)in order to run Windows on the 112mhz bus, but I ran into the same PIO thing on the hard drive so I gave up on 112. Something about overclocking the PCI bus on the 503s that my drives choke on.

George



[This message has been edited by CMonster (edited 02-13-99).]

[This message has been edited by CMonster (edited 02-13-99).]

[Shelomo]

Good call on the PIO mode, I never would have thought of that. At any rate, it's a moot deal. Right now I'm running 400Mhz, 100FSB x 4. I was doing well at 2.5v but it wouldn't always boot, so I moved up to 2.6 and have been doing fine all day. QuakeII demo didn't die... Hey, another question about this board. The FIC site said the board has CPU temperature monitor, but I can't find it. Help? I'd like to know if anything's cooking. Doesn't seem that way though.