ASUS P5W DH Deluxe and Corsair TWIN2X2048-8500C5D

[vladimirus]

Hi,
I'm very confused (almost disapointed) with this memory.
My mb is ASUS P5W DH Deluxe and the processor is intel core duo E6700 @ 2.66.
I had 2 x 1 Gb Kingston KVR800D2N5/1G PC6400 @ 800 and the pc was really stable overclocked at 3.45 with 1:1

ratio and mem voltage 2.20, cpu vcore 1.46, fsb termination voltage 1.40, mch chipset voltage 1.55, ICH

chipset voltage auto.
I thought to buy Corsair TWIN2X2048-8500C5D to have fsb 1066.
1) I tried various combinations of timings and voltages and the pc was freezing, or windows crashing (blue screens with memory and cache messages). I understand from the forum that can't have 1:1 ration with 1066
but I also tried what corsair claims to work , that is 5-5-5-15 2T with 2,20 mem voltage @ 1066 and the pc was freezing at the vista boot screen. I raised the mem voltage without any luck. Note that even with the native speed 2,66 I couldn't boot.

2) This is my big question. Corsair claims that 5-5-5-18 @ 800 is verified for this memory. I tried several speeds (oc or not) with dram frequency from 266 to 1066 and I was luck to boot on windows, I get messages that various apps stop working and sometimes resets. I really dont understand why this memory can't work at least at 800 mhz.

With SPD or manual clock settings see no difference.

CPU Freq. 266 to 340
DRAM Freq (according to above)
PCI Exp. 100
PCI Clock Sync. Mode 33.33 Mhz
Memory Voltage 2.20 to 2.40
CPU Vcore voltage 1.40 to 1.48
FSB Termination voltage 1.40 (this is always stable)
MCH chipset voltage 1.55 (this is always stable)
ICH chipset voltage Auto

The truth is when I managed to boot with 1020, 1027, 1033 fsb and did some benvhmarks with everest I saw great mem performance. Orthos gives me errors very soon (3-10 min) with blend stress. The odd is when I do only cpu stress sometimes it can last 3h or more (manually stopped). But with ram stress in (2-5 min) I get errors.

Sorry for long length but tried to provide with some infos.

Regards
Vladimiros

[vladimirus]

I did memtest 1.70 with no oc at 2.66 the corsair memory and at 40% of the test gave me 540.000 errors !!!
I can say for sure that I have a bad part ...
Now my only question is should I replace the same memory or choose another one ?
With this one I have the 1:1 ratio problem.

What is the best corsair mem for my case (oc at 3.4 / best clock timing) ?
Is dominator series the best ?
Corsair site suggest :

Enthusiast TWIN2X2048-6400C4
Overclocker TWIN2X2048-6400C4D
Extreme TWIN2X2048-6400C3DF


TWIN2X2048-6400C3DF
JEDEC standard 5-5-5-18 values at 800MHz
EPP standard 3-4-3-9, 2.4V values


TWIN2X2048-6400C4DHX
Tested at latency settings (4-4-4-12) at 2.1V
JEDEC standard 5-5-5-18 values at 800MHz

TIA
Vladimiros

[Yellowbeard]

With Memtest, did you disable the Legacy USB Support for testing? There is a conflict with this setting and Memtest so it must be disable for testing purposes.

Also, your MOBO is not likely capable of running memory at 1066mhz and the PC8500 memory is not recommended for this MOBO. Either of the PC6400 memories you listed are better choices.

[vladimirus]

Hi , and thank you.
I didn't disable the Legacy USB Support.
Anyway, what are better timings ? 3-4-3-9 (TWIN2X2048-6400C3DF) or 4-4-4-12 (TWIN2X2048-6400C4DHX) ?

Regards
Vladimiros

[Yellowbeard]

3-4-3-9 (TWIN2X2048-6400C3DF) are the better timings. And, this set should OC much higher than the other PC6400 version if you should try to OC past PC6400 speeds with looser timings.

[Yellowbeard]

Also, you should easily be able to run your PC8500C5D and PC6400 4,4,4,12 timings or, possibly lower. I would troubleshoot and evaluate the memory you have before you decide to RMA.

[vladimirus]

Yellowbeard hi,
I tried on kingston 4-4-4-12-6T and worked just fine 3.5 Ghz at 700. I have some questions if you like to help me a little more.
1) What are the lower timings you mentioned and what else should I change to try them ?
2) The "DRAM write recovery time" what values should have (how is related with the rest of the timimngs) ?
3) At the BIOS boot screen (with 4-4-4-12-6T) I see PC5300 (not PC6400) . Is this 'cause I have DRAM Freq 700 and not 800 ? If yes, how cpuz gives me 1:1 ratio ?

PS: I really like to have the corsair memory but as I said , I can't have a stable profile even when i'm not oc'ing (266 @800. PSD or manual timings).

TIA
Vladimiros

[Yellowbeard]

1) Try 4,4,4,12, at 2.1v. If it is not stable, give it 2.2v
2) Leave this at the MOBO default
3) The info you see at the bios boot screen may or may not be based on the SPD, not the actual speed you have set. What is your FSB and what does CPU-Z show for for FSB and for memory speed under the memory tab?

[vladimirus]

CPU tab
core speed : 3464.1
multiplier : X 10
bus speed : 346.4
rated fsb : 1385.6

MEMORY TAB
Frequency : 346.4
FSBRAM : 1:1
4
4
4
12
16

[Yellowbeard]

MEMORY TAB
Frequency : 346.4
FSBRAM : 1:1

DDR speed when at a 1:1 ratio: FSB x 2 = DDR so, 346.6 x 2 = 692.8. which you could round to DDR700. You will need a FSB of 400 to run the memory at 1:1 and get DDR800.