Memory timings - assistance needed

[Piezor]

Hi all. I'm wondering if i can pick your brains.

Overclocking in any fashion is not something i've tried before and something that i've always been wary of, but since a lot of manufacturers these days offer a valid warranty on overclocked items I'm more inclined to give it a go. Anyway, on with my problem.

I recently bought some RAM from OcUK at a steal of a price (OCZ 4GB (2x2GB) PC2-6400C5 Dual Channel Vista Gold Series DDR2) to accompany my existing 2GB of RAM (2xOCZ 1GB DDR2 800MHz/PC2-6400 System Elite Memory). There was a slight difference in the timings on the 2 types but I imagined this to be rather simple to fix, however, I've had some instability when adjusting the timings.

Basically, the old ram has 5-5-5-15 timings and the new ram is 5-5-5-18.

Now after stumbling around wrongly assuming i know what i'm doing the system blue screens or locks up when the timings are set manually at 5-5-5-15 and the same if set at 5-5-5-18. I even set it to auto config in the bios and it set the timings at 6-6-6-31 but was still unstable.

I updated the bios on saturday and the system is now stable when the timings are auto set but obviously i'd like to get the most out of the ram.

My question, then, is - If i increase the timings do i have to set them to a common factor of the clock/multiplier of the board or can i literally just set them to whatever i want (within reason obviously - ie 5-5-5-15 i'd be happy with, a little more wouldn't hurt ). Also, if i increase the timings do I need to increase the vdimm voltage and, if so, what to (do i need to scale the voltage with the 'overclock' somehow or just set it at 2.1v and hope for the best)?

My current rig is as follows:

Asus P5N-E SLI 650i
2 x OCZ 1GB DDR2 800MHz/PC2-6400 System Elite Memory (5-5-5-15)
2 x OCZ 2GB PC2-6400C5 Dual Channel Vista Gold Series (5-5-5-18)
Intel Core 2 Quad Q6600 B3 (2.4GHz)
Arctic Cooling AC-FRZ-7P Freezer 7
XFX 512MB 9800GT

I'd also be interested to know how far i could overclock my processor on the heatsink fan assembly I have, should the mood take me.

Any advice is much appreciated

 

[rjk]

hi - and welcome to the forums

do you have two different sets of memory in?
are each set running in corresponding lanes? [dual channel mode]
also your memory should need to function at the rate of the slowest rams timings
mixed memory is never a good idea

it just creates problems

have you overclocked your CPU at all?
on your setup you should at least be able to do 3ghz
maybe at stock volts

try fsb of 333
set multiplier to 9
set your ram to its rated speed with the fsb strap

and use stock timings
and stock ram voltages

post up some pictures of your bios overclocking screen and i will see if i can help you further

 

[Piezor]

Swift response

Yes the ram is different and yes they are in corresponding lanes (2gb sticks in 1&3 and 1gb sticks in 3&4). Worst case scenario is that i buy another 4gb bundle to match it but thought I'd try get it working using what i've got.

I'm at work at the moment but will be sure to get some shots of the bios when i get home. The bios does seems to be fairly flexible and allow me to change anything i'd need to whilst i've been poking around.

Thanks for the help matey. Will get back to you this evening.

 

[Piezor]

Okay, didn't get much time last night after work and football and laptop testing /sigh but I've found some shots of my bios online.

AI settings for preset overclocks which i'm dubious of but you can set the voltages etc in here manually.

CPU clock settings

Memory timings

Again, these are screenshots of the same bios but not my system, so i don't have a 3.8Ghz dual core thing in mine and am running the q6600 at stock speed 2.4ghz.

Thanks again for your help.

 

[spookywillow]

i can imagine its going to be one of the more advanced timings, install the slower set and use everest or memset to grab the stock timings and then set those accordingly in bios.
install new stuff and hope for the best, might want to increase your MCH voltage a notch too.

 

[rjk]

i can imagine its going to be one of the more advanced timings, install the slower set and use everest or memset to grab the stock timings and then set those accordingly in bios.
install new stuff and hope for the best, might want to increase your MCH voltage a notch too.

this -


also - do you really need more than 4GB?
i max my pc out with HD video editing [as well as a few other things open]
and it never maxes out the ram

i know the phrase - if you got it, use it
but if it compromises stability and the speed of the newer ram - is it worth it?

you could go 333X9 [3GHz] on stock ram settings and little voltage increase and see much more performance than if you highly tweaked your ram

 

[Piezor]

Yeah i think it's probably best to ditch the old ram, I'm sure i can find somebody who can make use of it

Will try taking the cpu to 3Ghz tonight and let you know how i get on