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TWIN2X2048-6400C4 (1g x 2) and Asus P5N32 SLI SE Deluxe = no-go at 800mHz?


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Dear Ram Guy:

 

I recall hearing that 2.1V works with two modules (2x1g) at 800mHz, but mine never passes memtest86+ (2.01) at 800mHz- always fails on test 7. I sort of ignored the problem until I begain running two 8800GTs in SLI and started getting hard shutdowns. Memtest shows one error every time in test 7- haven't gotten to test 8 and haven't tried one at a time.

 

Here's why: I found this comment from you in this thread. Is this still true with 0901 BIOS?

http://www.asktheramguy.com/v3/showthread.php?t=54422&highlight=6400C4+P5N32+SLI+deluxe

"I have tested this MB with these modules and it will run one at DDR800 but I would suggest using the memory at DDR2667 with this MB and over clock your CPU for best performance!"

 

Yikes- you mean that I cannot run more than one module at 800mHz? Please explain. I've tried 2.1V to no avail (with two modules). I've not tried 667 yet-and why would I? I paid for a mobo that declared all over the box that it supported DDR800.

 

Also consider that there's a section in the mobo manual (p. 2-39) that calculates power requirements- one example lists a rig with 4x256meg DDR2800. Where does anyone get 4x256 meg dimms? 1 gig is not enough anyway. Something is very fishy about that.

 

Please enlighten me.

Thanks!

-L

 

P5N32 SLI SE Deluxe (0901 BIOS, Nforce4 SLI x16 w/6.86 Nforce drivers)

X6800 Core 2 Extreme (Conroe dual core) @ 2.93 (stock clock)

Corsair CM2X1024-6400C4 (2 megs)

2x Zotak 8800GT 512 "amp" version (SLI, stock clocks)

RaptorX 150g HD (1)

Creative Labs X-Fi Xtreme Gamer

PC Power and Cooling T1KW-4E (1000W)

big Thermaltake case with large sidefan, multiple case fans

 

Win XP Pro 32 latest SP/updates

Nvidia 174.74 beta drivers (or 169.21 WHQL or 169.28 or 169.44)

Ntune version 5.05.54.00 (used only for manually setting GPU fans at 100%)

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With 2 modules you should be able to run at DDR800 with this board. The post that you linked to is about a year and a half old, and is probably no longer valid. Make sure you have the latest BIOS, and then load optimized defaults and set the Memory Voltage to 2.1 volts and then set the timings to 4-4-4-12 (CAS-tRCD-tRP-tRAS) and then test the modules one at a time with http://www.memtest.org! Please allow memtest to run 2-3 passes on each module. If you still get errors, we will be happy to replace them! However, if you get errors with both modules that would suggest some other problem and I would test them in another system or MB to be sure.
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*Critical discovery* Please review very carefully.

 

First, 0901 is the latest BIOS for the Asus P5N32 SLI SE Deluxe.

 

Now, the original problem framed by your old post (with an admittedly older mobo BIOS) was that one module at a time worked just fine @800. Therefore, testing them one at a time MAY not be dispositive, ie., if both work alone, they still may not work together anyway with this board, and the advice in your old post could still be correct.

 

I was going to do that anyway, but then I found something fascinating.

 

But first to the initial testing. I used Memtest86+ v2.01 (10+ repeated passes of all standard tests), with both modules tested simultaneously (both plugged into the mobo), listed by: FSB/DDR/timings/RAM voltage (also FSB voltage as applicable, listed as FSBV if changed). No overclocking of CPU multiplier during testing. USB Legacy support disabled in BIOS. 4-4-4-12-22-2T is verbose for faster timings; for the "auto" timing- no clue, but it echoed 5-5-5-15 (who knows what the last two #s were).

 

First tests done using stock FSB and by varying the RAM speed, voltage and timings:

1066/800/4-4-4-12/RAMV 2.1V = FAIL (test 7, every time)

1066/800/5-5-5-15("auto" mobo timings)/"auto" mobo RAMV = FAIL (test 7, every time)

1066/667/4-4-4-12/RAMV 2.1V = PASS (10+passes)

1066/667/4-4-4-12/"auto" mobo RAMV = FAIL

1066/667/5-5-5-15 ("auto" mobo timings)/RAMV 2.1V = PASS (10+passes)

 

So, using the stock FSB speed, the RAM works at 4-4-4-12 timings only at 2.1V RAM voltage and only when set at 667mHz. At "auto" mobo RAMV (~1.8V), only 5-5-5-15 timings (mobo's "auto" timings) work at 667. No settings allow 800mHz RAM- all fail Memtest86+ 2.01 during the first pass. Enabling/disabling mobo BIOS params "FSB Optimize Mode" and "Memory Optimize Mode" both together and individually in all combintations did not affect any of the tests. I left them both disabled (defaults) as a result.

 

NOW DIG THIS- then I located info on the 'net which seems to indicate that the FSB is the problem, ie., it's not fast enough throughput-wise at 1066 to accomodate the DDR2@800. Interestingly enough, the AUTOMATIC stock overclock params for this board (which I never use) list some higher FSB speeds for using DDR2@800. -lightbulb-

 

ET VIOLA!!!

1120/800/4-4-4-12/RAMV 2.1V/FSBV 1.315V (FSBV slightly higher than default)= PASS (15+ passes)

1200/800/4-4-4-12/RAMV 2.1V/FSBV 1.415V = PASS (FBSV 1.315V failed every time test 7)

 

As you can see, increasing the FSB from 1066 to 1120 or 1200 worked with 800mHz RAM setting and 4-4-4-12 timings at RAMV 2.1V. At 1120 FSB, I needed to increase the FSB voltage just one tick over default for best stability. At 1200 FSB, I needed to increase the FSBV to 1.415V, but that 1200 FSB setting was just for testing purposes- I won't use it.

 

I ran more than 15 passes on the 1120/800/4-4-4-12/RAMV 2.1V/FSBV 1.315V config. with never one error in any test. Bottom line? The RAM won't work with this board at 800mHz and 4-4-4-12 timings unless you o/c the FSB and run 2.1V RAMV.

 

Please explain. How is it that 1066 doesn't work but 1120 and 1200 do? What about all the values between 1067 and 1120 and 1120 and 1200? I don't have the time to find out. The selection of 1120 and 1200 comes from the auto overclock profiles that are listed/available in mobo BIOS. I never used the actual auto overclock profiles (changes too much, like RAMV settings that are too low); I did not use them to test the RAM either- I just got the idea to set the FSB to 1120 and 1200 by reading about them.

-L

 

P.S. This did not, however, resolve the hard crashes with Crysis and two 8800GT in SLI ;) --- Nvidia drivers are still likely broken for G92 chipset and SLI w/XP32...

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I would recommend going back a revision with your BIOS and see if you have the same issues. Also, try testing the modules in the other pair of DIMM slots. Normally errors on test 7 in memtest would indicate a configuration issue, or some other hardware problem than the memory, such as a weak or failing memory controller/DIMM slot. One more thing to try would be to increase northbridge voltage to 1.45v, and FSB to 1.3v with the CPU running at 1066MHz FSB, and see if it is the voltage that is getting the modules to work at 800Mhz.
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I noticed that the BIOS setting "System Clock Mode" was set to manual with 1066/800 values. I set it to "auto" and set all the voltages to "auto" save the RAM (2.1V). Interestingly, the post screen shows 2.92gHz CPU with manual 1066/800 values in the "System Clock Mode" BUT it now shows 2.93 gHz with "auto" selected for "System Clock Mode" parameter. Why oh why? The should be exactly the same, no? Is there some fraction that "auto" setting is taking into account?

 

Well, I ran Memtest86+ 2.01 again (still 0901 mobo BIOS) using:

"auto" (which was set manually to 1066/800)/4-4-4-12/RAMV 2.1V/all other voltages, including FSBV, to "auto"

 

Guess what? PASS.

 

For crap's sake- could it really be that simply setting the "System Clock Mode" to "auto" instead of manually setting it to 1066/800 did the trick? In auto mode, all tests report that it's set at 1066/800 anyway! So why would manually setting it to 1066/800 cause it to fail?

 

Back to more tests to verify. I will advise very shortly. Thanks again so much!

-L

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Hi-

 

Well, now it works all day and night. At any reasonable FSB/RAM/V etc. setting! I cannot understand why.

 

Here's my best guess: for many months, I've noticed that the two USB devices that I use (both are FullSpeed 2.0 spec)- Thrustmaster HOTAS Cougar and Logitech G9 mouse- aren't always powered-up on boot. Needed to reboot twice somtimes for it to work.

 

Long story short- a while ago I disconnected both of them and ran memtests. Of course, I always disable Legacy USB support before running Memtest. Still, no go- still got failures in Test 7. After I first posted here, I got the wild idea to set PlugNPlay OS in my mobo BIOS to "Yes" for the first time ever. In older builds (win98), that was a big no-no. BIOS had to assign IRQs, or things would go bad very quickly indeed. Heard that with XP, it would actually be a good idea to try.

 

Anyway, set PnP OS to "Yes", rebooted w/USB devices connected, opened Device Manager, immediately noticed that the USB and PCI host controller IRQs were changed by windows (probably other things as well). Please note that there was never any conflict, IRQ or otherwise, reported by XP, even when I used BIOS to set IRQs (PnP OS to "No"). Restarted PC and ran Memtest86+ 2.01 and Memtest 3.4a (Chris Brady) dozens of times from DOS. Pass. Then I wrote my f/u post here indicating that suddenly, I could not get the RAM to fail (see just below).

 

This is the only reason I can think for why the RAM now works, but it makes no sense. I didn't change anything else! WTH? How could this have worked? Can you shed some light?

 

At least it works!

-L

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I really couldn't tell you why changing PnP OS would get your system to stabilize, however if it is changing IRQs then its possible you had an IRQ conflict previously. As you said, at least its working now, let us know if you have any problems in the future!
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  • 2 weeks later...

This is to you both.

 

I have been following this thing because I am having hard crashes too. Not only in Crysis, but random crashes as well. Mostly on a install of some big program the install will end with my system dead.

 

I now have the PnP setting to yes (Vista 64 is my OS) and I am giving it a go installing a program which crashed on me before. If it runs clean I am going to try Crysis. I only get the crash on a certain point in a big level when the comp seems to be at a point of loading a new field.

 

I am interessted:

 

Did you experience random crashes?

With the PnP yes is your system fully stable?

Even in Crysis?

 

And can you run at 4GB? (I remember you ran XP so I dunno)

 

 

regardz

 

MorgothG

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Morgoth, Please make sure that you have the latest BIOS for your motherboard and then load optimized defaults and set the Memory Voltage to 2.1 volts and then set the timings to 4-4-4-12 (CAS-tRCD-tRP-tRAS) and then test the modules one at a time with http://www.memtest.org! Please allow memtest to run 2-3 passes on each module. If you still get errors, we will be happy to replace them! However, if you get errors with both modules that would suggest some other problem and I would test them in another system or MB to be sure.

 

Let us know the results!

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Dear RAM Guy,

 

Updating the BIOS caused a little sweat and headache.

 

After updating to 1403 via Asus EZ Flash. The system went dead. Just the fans spinning no beep from the mobo. So with a lot of effort I found the jumper en resetted my BIOS.

 

So I am not getting any further. Any suggestions?

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I am not trying a BIOS update soon (unless you've got a tip for the afore mentioned problem) But on the QVL for the MOBO I read that the bord is only stable with either 1 or 4 banks of mem.

 

I got ridd of number 4 in order to get Vista operating. Now I plugged in all 4 and I am up and running (have not tried a install of big software yet) and all seems good.

 

Could perhaps the instabliaty come from the mobo with 2 or 3 banks of mem instead of the 1 or 4?

 

Goodnight. Tomorrow I will try a install. I am just glad I got all up and running again.

 

Thanks in advance

 

MorgothG

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If you are having trouble updating the BIOS you may want to contact ASUS. Its usually a good idea to update the BIOS first, as it can resolve many issues, however if you can not update it then I would just load setup defaults, configure the tested settings for the memory and then test them one at a time with memtest.
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