Memory timings help!

[SilentSuicide]

Ok today i made the switch from 2x256mb Mushkin PC-3500 to 2x512mb OCZ PC-3700 EL Platinum (getting this for the extra MB and going to use this in my future Athlon 64). My setup is as seen in my sig, XP3000 (400fsb) running @ 210fsb giving me 2210mhz (XP3200) i wont go into the overclock as this is the highest i could go with this crummy cpu and still remain stable (i have a feeling this was supposed to be a XP3200 that couldent "cut the mustard" so it was rebagged to an XP3000) Then i decided to play with the memory a bit.

Soooo at 2,3,3,6 timings (with NO voltage tweaks, and the timings i was originally running the Mushkin at. Unfortunately i didnt save my Mushkin timing results ) i ran sandra and got a score of 3126 (integer) and 2921 (float)

Then ran 2,3,3,5 and got 3099 (integer) and 2893 (float). Both of these reported Max mem. BW @ 6720 and max bus BW @ 3360.

Lastly i decided to really crank things down and ran 2,2,2,5 (Mushkin could do these timings but they produced so weird laggy results, so i backed off to 2,3,3,6 (which was the most stable) and had been running at those timings ever since), anyway i pf10 to save, and i couldent even get to my bios screen. The system locked up and i had to do a powersupply switch off, then restart. When the bios screen came back on it said something about being in safe state and the cpu was being run at 1050mhz, so i went into bios to investigate and the settings were atill at fsb210 and the memory timings were still at 2,2,2,5.

My next step was to increase the voltage to the mem up to 2.7 and the cpu to 1.7 and chipset to then next level. pf10 save then NOTHING! Same thing, it wouldent even get into the bios, the screen was black and the system locked. SO i went back and ran the 2,3,3,6, put the voltages back to default, and everything was fine again.

What do you guys make of this? I know the memory is rated at 2,3,3,8 and i have seen benchmarks with the memory as low as 2,2,2,5 and it just screamed. Do my previous scores look acceptable? Anyreason why the Mushkin would boot at 2,2,2,5 and these OCZ wont? And why does 2,3,3,6 produce better results then 2,3,3,5? Maybe i should just be happy with 2,3,3,6. I want to point to this silly cpu as being the problem but maybe im wrong. Heh this cpu was just supposed to be a stop gap from my older XP1900 until i get the Athlon 64 in the spring.

 

[BigBadBiologist]

It makes sense because every memory in every setup is different. One thing you could try is adjusting the tras and others separately (e.g. 2,3,2,6 vs 2,2,3,6). As far as the banchmarking goes, try some real gaming benchmarks and see if the oddness is consistent.

 

[AristoV300]

I would bump up your vdimm at least to 2.8, they should be rated to run that high.

 

[BonzaiDuck]

OCZ's philosophy on timings departs from commonly-held folklore about bandwidths. I cannot comment on these specific Platinum PC3500's, but the idea is basically the same. Somewhere in the industry news (sorry, but I forgot the e-magazine and date -- but '04 for sure) -- OCZ made this clear. CAS latency is not necessarily the most important factor in improved bandwidth. OCZ has looser timings, but they have also implemented certain "optimization" features of their memory modules to get better bandwidth.

And in general, you get more bandwidth by boosting memory bus-speed in megahertz than with tighter timings at the same bus-speed.

The other thing to do -- as mentioned before -- is to bump up the voltage. Check again with these Platinums, but more than one model of OCZ memory module is warrantied for life up to 3.0V VDIMM.

If your motherboard only allows adjustment up to 2.85V and you want to go higher, try this:

DDR Booster

You'll need an empty DIMM slot. I assume since you have a dual-channel matched pair of 512's, you still have two slots empty. Also, go to OCZ Technology and find the motherboard compatibility list for this item. It DOES seem to have a formidable list of mobo applications!