More P4C800 Woes (hyper-x RAM)

[somagaze]

It seems Kingston has made RAM too fast for the 875 chipset. I'll start with my setup:

P4 2.8GHz (800MHz FSB)
ASUS P4C800 Deluxe
2 sticks Kingston PC3200 512MB (hyper-x) KHX3200AK2/1G

When I boot up, i get a 200MHz external clock, x14 multiplier for the CPU and dual channel RAM running at 400MHz.

Now, I am new to the workings of RAM (learning as i go today), but i was reading somewhere that the motherboard incorrectly sets the speed of the RAM. I found from kingston that the RAM is:

Timing reference: 2-3-2-6-1 <--Not sure what this means...


On the mobo, i can manually change (orignal numbers on the left)


2.5 - CAS# latency
4 - RAS# Precharge
4 - RAS# to CAS# Delay
8 -Precharge Delay
4 -Burst length

maybe the 2-3-2-6-1 relates to this? if you go in order down the list referencing 2-3-2-6-1, that would be the easy fix...but

the final timing reference # (1 for the RAM) is not an available option for Burst length (only has 4 and 8)


Can someone please help? and maybe you can explain what these mean. Thanks in advance...

[somagaze]

UPDATE -

I downloaded something called Aida32 that can display a lot of system hardware info. Under summary for my system it tells me i have a P4 2800MHz (3.5 x 800) <--this is what i want to see.

Under the mobo info it tells me i have a FSB real clock of 200MHz (QDR) what the "QDR" means, i don't know. But, it says i have an effective clock of 800MHz <-- looking good

It goes on to tell me (under mobo info) about my memory bus properties. The real clock is 200MHz, the effective clock is 400MHz.

So, if I am understanding this correctly, the double data rate RAM is processing on two sine waves 180 degrees apart giving the effective freqeuncy of 400MHz, and the 2 memory modules are in paralell on the FSB giving the FSV an effective frequency of 800MHz.

In conlcusion, if I am correct abou these assumptions, I am an idiot not to realize my system is operating fine... :rolleyes:

Hopefully someone can either verify this is correct, or give me the right answer. It would make my day if i knew i am actually taking advantage of a 800MHz front side bus...

[Someone Stupid]

Okay, your running it right. The ram's max stock speed is 400 mhz, double pumped like you guessed. A signal is sent on the beginning and end of a cycle. Thus you have a 2:1 ratio or vice versa for your mem timings to FSB (It's been awhile since I've toyed with Intel systems, but the ratio is one or the other). As for the FSB of the P4C, it is quad pumped. Meaning 200 FSB gets you an 800 FSB. You can go two ways if your looking to increase performance. The most common is to raise the FSB and relax the timings as needed, the other is to keep the timings as tight as possible. Both of these generally need a vdimm increase to work well the further you push it, especially in dropping latency quite often or heavy FSB raises - any other timings generally don't require much of an overvolt if they require any at all. Ram is safe to overclock the hell out of - I've yet to fry a stick and I've ran my memory at the max setting my Epox would allow it - 2.95 IIRC to keep tight timings after raising the FSB considerably as well. I used Corsair XMS though Kingston is generally my second choice if I'm building a system for someone and they want it OC'd - just I prefer Corsair, the sticks tend to be more predictable.

So if your running just fine. If you want to increase the processors speed, raise the FSB and memory speed if your board supports it, though mem speed doesn't have to match the CPU's FSB. So you could have a 220 FSB and a 210 memory clock, so when pumped you get 880 and 420 respectively. You will have to be able to add voltage to the ram to do this - getting a vantec iceburg will help as well to mount on your northbridge for better cooling. If you want to keep your current timings, you'll definantly need te vdimm increase, and if you want to tighten them on an overclock. Well add more voltage and pray that you have a module from a great batch, as it can be hard to raise the FSB real high and keep tight timings even with the voltage increase - after so much the added voltage just produces heat pretty much.

Oh, and before you start overclocking if your intending to, or if your not, set the ram to the manufacturers specs. They are tighter timings.

[somagaze]

Great, thanks for the help...its nice to know that my system is running as it should.

Now, for OC'ing. I 'm not sure what is meant by tightening the timings on RAM, in fact i don't even know what RAM timings are. I understand that they are displayed as "2-3-2-6-1" but i have no clue what each # means.

The board uses these numbers when i disable "configure bt SPD"

2.5 - CAS# latency
4 - RAS# Precharge
4 - RAS# to CAS# Delay
8 -Precharge Delay
4 -Burst length

Changing these numbers changes the memory's timing, that's the easy part...but which way do i change it? What does each number mean? And what does "tightening the timing" mean when referencing these #'s?

I'm basically looking for a little training in RAM 101, I would really appreciate it if someone would take the time to explain it to me.

Thanks!

[WiltshireTony]

I have just been jumping through the same hoops as you!

In answer to your question about 2-3-2-6-1, I believe this to be correct.

First 2 = CAS latency
then 3 = RAS precharge
2= RAS to CAS delay
6 = RAS active to precharge
1 = Command rate

Hope this helps you