Memory (AData 800MHz)/Mainboard (Asus P5NSLI) compatibility

[Pags]

I just purchased a new computer from an online retailer (name given on request) - those numnutz decided to install 2 A-Data DDR2 PC6400 800MHz 512MB memory (http://www.adata.com.tw/adata_en/product_detail.php?ProductNo=AD2800U) into my Asus P5N-SLI nForce 570 SLI mainboard (http://www.asus.com/products4.aspx?l1=3&l2=11&l3=331&model=1311&modelmenu=1) in dual-channel mode.

I was noticing that the computer was locking up frequently, so I gave the online retailer a call. Their tech support folks recommended that I jack up my DRAM voltage from "default" (which I think is 1.8V) to 2.1V. This seems to stabilize my system and it no longer locks up. However, I'm still concerned - the A-Data site (linked above) specifies a voltage of 1.8+/-0.1V to be used with the memory. The mainboard specification doesn't seem to mention 800MHz DDR2 memory as being supported - it mentions Dual-channel DDR2 667/533.

So, it appears that the memory is too fast for the hardware to handle, which might be how it's getting buggered up and locking my computer. The voltage thing seems to be balancing it out (possibly by making the memory less efficient?).

So, my question to you is - is it really okay to go 0.3V over the specified load (0.2V above "max") for the memory for long-term 24/7 computer usage (99% of the time with a pegged CPU)? Am I effectively overclocking my system and RAM by using 800MHz RAM (in other words, is what I've done at their behest a good thing)? Can this system be overclocked any further, or would that be asking for trouble? Should I get the computer manufacturer for false advertisement (they have "4 x DIMM, max. 16GB, DDR2 800 / 667 / 533, non-ECC, un-buffered memoryDual channel memory architecture" on the part specification for the motherboard) and have them upgrade me to an ASUS board that really can take DDR2 800 MHz - free of charge of course?

P.S. I can't seem to post to this forum from that computer. It keeps telling me to enable cookies, which I'm sure are. I have the default XP firewall in place though.

P.P.S. I posted this to the general hardware forum earlier, but it turns out that's more a CPU forum, and not a memory/motherboard forum. So I'll remove that post now if I can. Sorry, I'm a n00b

 

[Mondoman]

How do you know what speed the memory is being run at? Perhaps the RAM is being run at DDR2-667?
In any case, do the following:
1) First, make sure your memory really is running without ANY errors. Run the freely available memtest86+ program for a number of hours. Also, download and run PRIME95 (run one copy per core if you've got a dual-core processor) in stress-test mode and make sure you don't get any errors. It's the store's responsibility to supply you a system without any memory errors.
2) Second, find out what speed your memory is running at. Download PC Wizard 2006 and run it. Click on the "Mainboard" icon in the left column (computer case with green arrow pointing down). In the upper right, click on "Chipset" (not on Physical Memory) and look in the bottom right Information window. Under "Memory Information", what is the "Type" and "Frequency"?

Upping memory voltage is a standard way to stabilize memory at higher speeds; DDR2-800 technology is new and unsettled enough that boosting DIMM voltage is probably acceptable, as long as it doesn't exceed the maximum voltage limit specified by the DIMM manufacturer. The voltage spec you found is just the standard DDR2 memory voltage - you need to find out from AData what the max allowed voltage is before the warranty is voided. IIRC, Corsair specifies a limit of 2.1V on their premium memory, while OCZ allows up to 2.2V.

It does seem like the MB is not rated for DDR2-800, and that would explain why boosting the memory voltage was needed for the memory to run stably. You'll need to verify this with Asus.

In general, you get what you pay for. If the price was low, they are likely saving money on the component quality and/or level of support.

 

[Pags]

How do you know what speed the memory is being run at? Perhaps the RAM is being run at DDR2-667?
In any case, do the following:
1) First, make sure your memory really is running without ANY errors. Run the freely available memtest86+ program for a number of hours.

I did 3 passes (about 45 minutes?) and it hadn't detected anything yet.

Also, download and run PRIME95 (run one copy per core if you've got a dual-core processor) in stress-test mode and make sure you don't get any errors. It's the store's responsibility to supply you a system without any memory errors.

I can only seem to get it to engage 1 processor fully (50% of total load). Taskinfo reports the other one is only being drained about 10% of its load from prime 95, and the rest is on idle. I've tried setting process priority to high and it still isn't being greedy. I have XP home - is there anything in my system I should tweak to make it use more processor? On a side note, I usually run Seti@home(boinc) on this system and all results, regardless of voltage level, have validated with other users properly.

2) Second, find out what speed your memory is running at. Download PC Wizard 2006 and run it. Click on the "Mainboard" icon in the left column (computer case with green arrow pointing down). In the upper right, click on "Chipset" (not on Physical Memory) and look in the bottom right Information window. Under "Memory Information", what is the "Type" and "Frequency"?

"Type : DDR2-SDRAM PC2-6400 (399 MHz) "
"Supported Frequencies : 200 MHz, 266 MHz, 400 MHz "
"Voltage : SSTL 1.8v " - after setting my bios back to default
Both chips display identically here

Notice that it says 400 max...the label on the RAM chip says "DDR2 800(5) 512MX8". If it's 800MHz, shouldn't it be saying 800 or at least 667/533?

Upping memory voltage is a standard way to stabilize memory at higher speeds; DDR2-800 technology is new and unsettled enough that boosting DIMM voltage is probably acceptable, as long as it doesn't exceed the maximum voltage limit specified by the DIMM manufacturer. The voltage spec you found is just the standard DDR2 memory voltage - you need to find out from AData what the max allowed voltage is before the warranty is voided. IIRC, Corsair specifies a limit of 2.1V on their premium memory, while OCZ allows up to 2.2V.

It does seem like the MB is not rated for DDR2-800, and that would explain why boosting the memory voltage was needed for the memory to run stably. You'll need to verify this with Asus.

In general, you get what you pay for. If the price was low, they are likely saving money on the component quality and/or level of support.

Thanks for your advice and help so far.

 

[Mondoman]

I did 3 passes (about 45 minutes?) and it hadn't detected anything yet.

That should be enough. Looks like your memory is running fine w/o errors at least during idle/normal work.

Also, download and run PRIME95 (run one copy per core if you've got a dual-core processor) in stress-test mode and make sure you don't get any errors. It's the store's responsibility to supply you a system without any memory errors.

I can only seem to get it to engage 1 processor fully (50% of total load). Taskinfo reports the other one is only being drained about 10% of its load from prime 95, and the rest is on idle.

Yes, you need to set some settings. Essentially, you need to have two copies of the program, each in its OWN directory. Rename one PRIME95Core0 and one PRIME95Core1 (so you can keep track of them). Run the first copy. IIRC, there should be an "Affinity" setting in one of the program menus - select the first core for that program. Run the second copy of the program and set the "Affinity" to the second core for that program. Then, each copy should remember which core it is set for.

2) Second, find out what speed your memory is running at. Download PC Wizard 2006 and run it. Click on the "Mainboard" icon in the left column (computer case with green arrow pointing down). In the upper right, click on "Chipset" (not on Physical Memory) and look in the bottom right Information window. Under "Memory Information", what is the "Type" and "Frequency"?

"Type : DDR2-SDRAM PC2-6400 (399 MHz) "
"Supported Frequencies : 200 MHz, 266 MHz, 400 MHz "
"Voltage : SSTL 1.8v " - after setting my bios back to default
Both chips display identically here

Sorry, you didn't quite follow the instructions - you clicked on the "Physical Memory" line in the upper right window. That just lists the SPD info. You need to click on the "Chipset" line in the upper right window. Then, down in the bottom right window, "Memory Information" will show the actual conditions under which the memory is running. In particular, what does it say there for "Type" and "Frequency"?

Notice that it says 400 max...the label on the RAM chip says "DDR2 800(5) 512MX8". If it's 800MHz, shouldn't it be saying 800 or at least 667/533?

No, the "DDR" part stands for "double data rate", so a 400MHz memory bus speed transfers 400MHz x 2 = 800MHz data rate, or DDR2-800.

 

[Pags]

Yes, you need to set some settings. Essentially, you need to have two copies of the program, each in its OWN directory. Rename one PRIME95Core0 and one PRIME95Core1 (so you can keep track of them). Run the first copy. IIRC, there should be an "Affinity" setting in one of the program menus - select the first core for that program. Run the second copy of the program and set the "Affinity" to the second core for that program. Then, each copy should remember which core it is set for.

Yep, I figured that out, but in a different way - I run it from the command line as F:\Downloads\p95v2414\PRIME95.EXE -a1 and
F:\Downloads\p95v2414\PRIME95.EXE -a0

Then I specify the affinity in the menu as well.

Prime95 seems to get "stuck." Initially when I was running only a single copy of the program, it got through the first set of tests in about 30 minutes, then it went to a larger block size. Since I've been trying to run two processes simultaniously it's only gotten each set through about 1/2 the set. It's gone 4 hrs 48mins and it's only on the third test (on each processor), and processor usage was about 5% for either process. Both are "stalled" on test 3, 4000 lucas-lehmer iterations of M19374367 using 1024K FFT length.

Sorry, you didn't quite follow the instructions - you clicked on the "Physical Memory" line in the upper right window. That just lists the SPD info. You need to click on the "Chipset" line in the upper right window. Then, down in the bottom right window, "Memory Information" will show the actual conditions under which the memory is running. In particular, what does it say there for "Type" and "Frequency"?

Same info here too

Memory Information :
Type : DDR2-SDRAM PC2-6400
Frequency : 400 MHz
FSB/RAM Multiplier : 2/3x
Supported Channels : Dual (128-bit)
Activated Channels : Dual
ECC Diagnostic : No
CAS Latency (tCL) : 5 clocks
RAS to CAS (tRCD) : 5 clocks
RAS Precharge (tRP) : 5 clocks
Cycle Time (tRAS) : 18 clocks
Bank Cycle Time (tRC) : 23 clocks

Notice that it says 400 max...the label on the RAM chip says "DDR2 800(5) 512MX8". If it's 800MHz, shouldn't it be saying 800 or at least 667/533?

No, the "DDR" part stands for "double data rate", so a 400MHz memory bus speed transfers 400MHz x 2 = 800MHz data rate, or DDR2-800.[/quote]

okay...thanks for that bit of info. does that mean that it CAN work with a 667/533 board, since 400 is lower than either of those?

 

[waverunner]

I know this is a little late, but I'm replying cause I got the same problem and waiting for my new config to be delivered, anyway, I found this while searching if I could use the PC 6400 being supplied with my board and thought you might find it useful

http://www.anandtech.com/mb/showdoc.aspx?i=2820&p=6

Good luck