Memory question DDR900 vs 800

[tempoct]

I'm currently have E6300 OCing on P5B Deluxe with Corsair XMS DDR2-800 and try to get stable @ DDR2-900 (450MHz @ 5-5-5-15 2.15v). I can't get this stable. Orthos large FFT failed about half and hour. +0.05v seems do no good (get 5 mins more on Orthos).
I paid a lot for this RAM. Would I be better off buying DDR2-900? I saw the OCZ Gold DDR2-900 is actually cheaper than the Corsair. Maybe it's a better choice?

 

[cmdrdredd]

Originally posted by: tempoct
I'm currently have E6300 OCing on P5B Deluxe with Corsair XMS DDR2-800 and try to get stable @ DDR2-900 (450MHz @ 5-5-5-15 2.15v). I can't get this stable. Orthos large FFT failed about half and hour. +0.05v seems do no good (get 5 mins more on Orthos).
I paid a lot for this RAM. Would I be better off buying DDR2-900? I saw the OCZ Gold DDR2-900 is actually cheaper than the Corsair. Maybe it's a better choice?

The memory you have likely does NOT use Micron ICs. It doesn't seem to like certain speeds and voltages unless you get lucky. It's unfortunate, but let me ask this. Can you run 3dmark, sandra memory bandwidth benchmark, and games without issues? If you can generally use the system ok I wouldn't worry about it.

Orthos and memtest stress the memory in different ways than general usage and gaming. It's very possible for a system to never pass orthos but still pass memtest and you can game forever and never have a crash.

 

[tempoct]

Hi,
Thanks for your reply. I have played roulette with the RAM ordering. I should have ordered the Ballastix! (How can I tell if I have the Micron D9 or not?)
Anyway, what about DDR2-900? OCZ is selling that cheap. Would I be better off? Since it's suppose to be "guaranteed" DDR2-900 (I believe timing is like 5-5-5-15).
I have run 3DMark05 no problem. Haven't tried Sandra & Memtest yet.

 

[tempoct]

I guess I was wrong before. The mobo seems to hit the wall, not the RAM.
I retest last night and got RAM quite stable @ 480MHz (DDR2-960 5-5-5-15 2.15v) and @450MHz (DDR2-900 5-5-5-15 2.1v - stock voltage). Both have Orthos large FFT stable abiyt 1 hour (didn't test more). But my motherboard seems to hit stability issue @ "CPU Frequency" = 430.

What voltage to increase for mobo in this case?

 

[cmdrdredd]

You can try maxing the voltage and see how far it goes (northbridge voltage).

To tell what ICs are used on your memory you have to remove the heatspreader which can damage the memory perminately if you do it wrong. But there is a page Here that shows what ICs are used on various DDR2 memory.

The OCZ DDR2-900 uses Micron D9GKX which is supposed to be the top overclocker right now. The next best is Micron D9GMH which can overclock really well. The main difference is the D9GMH is DDR2-667 certified and the D9GKX is DDR2-800. So it starts higher. Although certain companies like Corsair, Mushkin, and Team can and do bin the D9GMH to run at DDR2-1100+ or really tight timings. Corsair sells a PC8888 which is DDR2-1111 set, Mushkin has their Redline series DDR2-1000 that starts at cas4 (usually memory is cas5 at this speed) and can overclock to super high levels too. Team even had a set out (only 20 sets made and never to eb released afaik again) that did DDR2-1000 at 5-4-4-10 and people have ran it at DDR2-1200 at cas4 (with active cooling).

 

[tempoct]

Ran out to my local Fry's and try the DDR2-900 OCZ on my board but it didn't boot. Try increasing the Vdimm to 2.1-2.2v also no boot. Might be compatibility issue with the board. I have returned the RAM.
I will try to increase NB to see of I can run the mobo at higher speed.

 

[cmdrdredd]

Originally posted by: tempoct
Ran out to my local Fry's and try the DDR2-900 OCZ on my board but it didn't boot. Try increasing the Vdimm to 2.1-2.2v also no boot. Might be compatibility issue with the board. I have returned the RAM.
I will try to increase NB to see of I can run the mobo at higher speed.

It should work. There is no such thing as "imcompatable memory" only a BIOS with bugs. Hence why you see updates addressing memory "issues"

It could be that the OCZ was bad. Did you try a cmos reset before installing?

 

[tempoct]

Well, I did try 2.2v. The way I could get that is plug in the Corsair, set the bios and then shutdown and swap RAM. No luck.
Maybe bad bios like you said.

 

[cmdrdredd]

Originally posted by: tempoct
Well, I did try 2.2v. The way I could get that is plug in the Corsair, set the bios and then shutdown and swap RAM. No luck.
Maybe bad bios like you said.

Well, they did release a BIOS that specifically stated it fixed some compatability problems with OCZ. It could just simply be the timings used with the particular ICs on a specific revision.