OCZ EL Rev.2 and Default RAM voltage

Anyone know the default ram voltage of the P4C800E Dlx?

I got my new OCZ sticks and 2225 was working fine but last night I got my first ever "random" restart in 2 years on this PC. My Enermax PS is the old-school "tough" model and never fluctuates more than .02 on the 12v rail so I was wondering if the ram could have been culprit.

OCZ states the voltage is 2.75...I had the board set to auto. I assume, like some sort of voltage spd, the MB would know it needed 2.75 ans issue that.

I have since set it manually to 2.75...but I have that yucky feeling that something else could be lurking.

So can someone verify that by setting the DDR voltage to AUTO I was in fact slightly undervolting the RAM?

I am confident it isn't the PS. The only thing that has changed is the RAM.

Shane

Try 2.6v, I had problems at stock at 2.8v before too. Auto? Whats that heh heh.

At stock speeds, some TCCD has issues with slightly higher VDIMM voltages. A lot of people find that anything above ~2.7V is counter-productive to stability untill you start actually overclocking the sticks.

BH-5 is strangely similar, and often errors when run at low speeds with a high VDIMM voltage, where the RAM is otherwise stable at heavily overclocked speeds. Example: the sticks are unstable at 200 MHz 2-2-2 given 3.5V, yet stable at 250 MHz 2-2-2 when given 3.5V.


My speculation is that this phenomenon has to do with a much stronger voltage-high value (a heavily overvolted VDIMM) throwing the voltage-high signal above transistor tolerance - but only when the frequency is low enough to actually allow enough time for the voltage high signal to peak and get close to the heavily overvolted voltage high value.

When we overclock our frequency, we tighten the amount of time allowed for the voltage high signal to transit from 0V to whatever value the voltage high is set to - which will bring our voltage high signal back down (the signal cannot completely transit to the 'peak' voltage high value because insufficient transit time is allowed - the signal transit frequency is increased/overclocked) within transistor tolerance, meaning stability. So, excessive overvolts go hand in hand with a frequency overclock if stability is to be maintained (if voltage high is to stay within transistor tolerance).

Speculation, but I'm pretty sure that it has some merit

If you are worried about any other problems try running memtest for a bit and see if there are errors. If not then the RAM isn't the problem

In case this has never come up, don't trust your voltages read by the onboard monitor IC. More often than not, they are incorrect, sometimes a lot. You need to check the voltage at the slots with a real Digital MultiMeter and establish a correction factor for the onboard readings. After that, you can just apply the correction factor to the readings you get. I have the correction factors for my board pencilled on my case for Vcore, Vdimm and Vagp. If you don't own a DMM, and I can't stress enough that every serious overclocker should own one, borrow one for an evening. If you can't figure out where to get the appropriate readings on your motherboard, post to that particular motherboards forum and someone can help you out.

Hoot

So far since setting the voltage to 2.75 in the bios I haven't had any issues. MBM doesn;t give me voltages for the ram anyway, so I can't really check what the ram is actually getting.

I was really just wondering what voltage the MB gives the ram when it is set to AUTO. Does it know what the ram wants (2.75)? Or does it just give 2.55 since that is what most stock ram requires...and they expect that if you have higher performance ram you'll set it yourself anyway?

Shane

Category 5 said:

So far since setting the voltage to 2.75 in the bios I haven't had any issues. MBM doesn;t give me voltages for the ram anyway, so I can't really check what the ram is actually getting.

I was really just wondering what voltage the MB gives the ram when it is set to AUTO. Does it know what the ram wants (2.75)? Or does it just give 2.55 since that is what most stock ram requires...and they expect that if you have higher performance ram you'll set it yourself anyway?

Shane

Click to expand...

Shane, that's probably going to vary from motherboard manufacturer to manufacturer as I don't believe the recommended voltage is set by the SPD. That's based upon the fact that these OCZ are supposed to be run at 2.75V and when I set the dimm voltage to AUTO in the BIOS, they come up at 2.70V. Again, that is with my MSI Neo2 Platinum. I can't speak for other motherboards.

Hoot

Hoot,

How are you able to tell what the ram voltage is when it is set to auto? Is there someplace in your bios or is there some other way to tell?

Shane

Category 5 said:

Hoot,

How are you able to tell what the ram voltage is when it is set to auto? Is there someplace in your bios or is there some other way to tell?

Shane

Click to expand...

I measure it at the dimm sockets with a Digital MultiMeter. Every overclocker should have one. Costs about as much as adding worthless cold cathode lights to the interior of the case.

Hoot