Unstable: ASUS P5N-T Deluxe w/ TWIN2X2048-6400C3DF

[DJTachyon]

I have put together my ASUS P5N-T Deluxe System with the TWIN2X2048-6400C3DF.

I cannot get the system to run stable with 3-4-3-9 timings @ ~2.4V. The ASUS utility says I am running the memory at over 2.5V though.
Should I believe the BIOS or the ASUS Probe?

At 4-4-4-12 timings, it runs fine.

Here is my setup:
ASUS P5N-T Deluxe 780i Motherboard
Intel Q6600 Quad Core
TWIN2X2048-6400C3DF
EVGA 8800GT Superclocked (650/1900) PCIe2.0
Western Digital 750GB RE2
Enermax Infiniti 650W EPS12V Power Supply

Any thoughts?

Thanks,
********

[DJTachyon]

I spoke too soon, 4-4-4-12 is not working either.
I am still having problems with stability, but this seems the best so far:

3-4-3-9, 2T Timings, Trc = 22.
2.25V in BIOS (Appears as 2.35V in ASUS AI Suite)

Any other thoughts on how I can get this more stable?

My stability result is always the same, a hard hang, no blue screen, just frozen.

It happens anywhere from bootup, to hours later. During both heavy and light loads.

[DJTachyon]

Okay, when I get home I will try this, let me know if its a good idea:

ASUS AI: Standard
- All Memory Settings: Auto
nVidia GPU Ex: Enabled
nVidia SLI-Ready: Expert

That should auto-configure the system for the EPP SPD settings, correct?

Has this worked for other 680i/780i boards, or is this an issue?

[RAM GUY]

I would set the memory Voltage to 2.4 Volts and set the command Rate to 2t and set SLI ready memory to CPU 0% and disable legacy USB and then test with www.memtest.org.

[DJTachyon]

I am actually running this with no problems so far:

ASUS AI: Standard (I would like to set to Auto)
- All Memory Settings: Auto
nVidia SLI-Ready: 0% OC

Do I really have to force to 2T/2.4V with SLI-Ready set? How do I know what the BIOS is doing? How do I know which settings they are really running at?

According to the ASUS AI Suite, the memory is running at 1.85V (not that I really believe it)

Didn't touch Legacy USB, why would that make a difference?

[RAM GUY]

If the system is stable then leave it where its at.

[DJTachyon]

I have tried all your suggestions, and by simply running SETI@HOME for 10 minutes, the system hangs.

I am currently at:
SLI-Ready: OC 0%
Memory Voltage: 2.390 (in BIOS)
Command Rate: 2T
Disabled Legacy USB

I haven't see the CPU temp go over 135degF.

[DJTachyon]

Ram Guy,

I have tried voltages from 2.190 - 2.390 as well.

MemTest86 gives me no errors.

But the system is still hard locking under load.

It must be a timing/voltage issue?

I really hope I can get what I paid for out of these things, if I go to CAS4, I could have got that memory for $40, not $250.

[RAM GUY]

Hard locking might suggest some other problem, and Do you have the memory fan installed?

[DJTachyon]

Yes the memory fan is installed, the ambient temp in my case is a balmy 102degF according to ASUS Probe though.

[RAM GUY]

Let's get them replaced, please use the On Line RMA Request Form and we will be happy to replace them.

[DJTachyon]

What do you think they will get replaced with?

What would be equivalent to DDR2-800 @ CAS3?

[RAM GUY]

There is no replacement for that part, but they will likely offer you a few choices. Please call our customer service at 888-222-4346 or http://www.corsair.com/en-us/company/contact Ext "0" after 8:00 AM Pacific Time tomorrow!

[xJom]

There might be an incompatibility issue between P5N-T Deluxe and Q6600. I know one person in Sweden and one in Norway that reports exactly the same behaviour as DJTachyon.

Edit: And now one more in the UK, also see: http://vip.asus.com/forum/view.aspx?...Language=en-us

regards
/xJom

[DJTachyon]

Well ...

The most stable I can get this thing at the moment is with the following settings:

ASUS AI Tuning: Standard
SLI-Ready Memory: CPUOC:0%
Command Rate: 2T
Legacy USB Support: Disabled
Memory Voltage: 2.310

But under very heavy loads .. it is certain to hard lock/hang. No errors, no BSOD, just hard video/keyboard/system lock. Windows has no clue it happened.

I have upgraded to the new 0502 BIOS with no change in results.