Can anyone answer a few questions about overclocking memory?

[The Sauce]

So I have my Opty 165 comfortably o/c'ed at 2.565 GHz (9 x 285) for a while now so its time to start working on the memory. Here are my questions:

1.) As you are overclocking the memory, which latencies do you start loosening and in what order?

2.) What program do you use to stress test your memory (other than Memtest86 which I think we all know isnt' worth a damn for that purpose)?

 

[bjc112]

2.) What program do you use to stress test your memory (other than Memtest86 which I think we all know isnt' worth a damn for that purpose)?

Whoever told you that is misinformed..

The windows version maybe, but boot off a floppy disk, or have a board tha has it built in, and memtest is GOLDEN.

 

[Porter21]

Memtest is very popular and works well.

 

[RichUK]

Well if you hadn?t researched your specific sticks, and was unsure on their capabilities. I would recommend that you loosen the timings to CAS 3 TRCD 4 TRP 4 TRAS 10, and up the RAM to its max rated voltage i.e. 2.85v ? 3v (BH5 is an exception, unless you wanna burn your sticks). If you relax the timings anymore you are going to receive to big of a performance penalty hit that you will not be able to compensate with high frequency, not to mention most DDR DIMMS are not built to run at the timings higher than that so you may see some adverse effects, and also they may not help with an increase in frequency.

Ok moving on, if you now keep increasing the 1:1 RAM clock (HTT) on say a CPU multi of 8 and find out what you max stable clock at 1T, and 2T frequency is by upping the frequency in periodic increments, 5Mhz etc, and keep testing via memtest. Your boards max HTT is also a dependant factor aswell, so test the max on this first, otherwise you will be limited by the board itself. Once you have reached the desired speed you can then try and tighten up the timings, depending on how high of a 1:1 frequency you have reached I would imagine you will be stuck with your CAS timings, however your other timings maybe able to tighten up, once again test with memtest when you do so, 5 and 8 are the most preferable.

To be fair I would read some reviews first on your sticks to see the average parameters, with regards to clock/timings.

This is a very basic way to clock the RAM, its quick and effective. But at the end of the day as Zebo proved a high memory frequency is not always beneficial on AMD 64?s, so using a RAM divider is always a decent option.

Oh and to be fair memtest is really the definitive application to whether your RAM is stable or not.

I helped someone before with RAM i knew alot more about

 

[The Sauce]

Ok well I guess we disagree about Memtest. I have had a few instances where there was a defective stick of memory that would give all kinds of system instability, fail Prime blend in 2 minutes, but pass Memtest86 for 10 hours... I would not trust that program father than I can throw it...which is nowhere.

And my original question did not get answered. I know HOW to overclock the memory...i just am not sure about what order to start slackening the timings in as I start getting errors. i.e., do I lower the tCAS first? ot tRas? I dont want to START with the worst latencies and work my way back up....that's just backwards.

So stock latencies for my memory (G.Skill ZX 2gb kit) are 2-3-2-5 @ 200 MHz. So if I get to 210 and start getting errors do I do 2.5-3-2-5? or 2-3-3-5, or 2-3-2-6? Which one do you start slackening when you hit a limit and in what order do you loosen them?

 

[RichUK]

Originally posted by: Snatchface
Ok well I guess we disagree about Memtest. I have had a few instances where there was a defective stick of memory that would give all kinds of system instability, fail Prime blend in 2 minutes, but pass Memtest86 for 10 hours... I would not trust that program father than I can throw it...which is nowhere.

And my original question did not get answered. I know HOW to overclock the memory...i just am not sure about what order to start slackening the timings in as I start getting errors. i.e., do I lower the tCAS first? ot tRas? I dont want to START with the worst latencies and work my way back up....that's just backwards.

So stock latencies for my memory (G.Skill ZX 2gb kit) are 2-3-2-5 @ 200 MHz. So if I get to 210 and start getting errors do I do 2.5-3-2-5? or 2-3-3-5, or 2-3-2-6? Which one do you start slackening when you hit a limit and in what order do you loosen them?

well i suggested that scenario since you have a 165 which runs on a x9 multi, so a higher frequency would be more preferable, would it not?

Basically the CAS timings is the most important timing as it reflects the biggest performance impact, much more so than the others. I would say that if you relax the TRCD and the TRP to say 4, and then push the frequency stably as high as you can on CAS2, and then CAS 2.5 if you need to obtain a higher 1:1 frequency, then tighten up the timings on TRCD and TRP. To be fair the best way to optimise and OC memory is to trial and error, as each config can be unique in nits own. With the TRAS timings this has next to no impact on performance, and should be set at either 7 on an NF4 chipset or 10 on a NF3 chipset, this has been documented before to be the sweet spot no matter the RAM frequency.

I understand what you are asking, basically how do you interoperate the errors thrown back in memtest, i.e. which test, tests which timings, so to fathom out what s holding you back. As there are not a great amount of variables I would just use the method I have stated above, and basically just see how far you can stretch the CAS2 and CAS 2.5 timings, and fit the TRCD and TRP timings around the best ?frequency / CAS timings?, as this will produce the best performance , which is what you seek right?

 

[The Sauce]

Exactly. You rule. Thanks for the help.