Additional 2x512MB sticks of PC 3200 RAM: no DDR 333 SPD data - problem?

[PianoMan]

For those of you with DFI boards, you know the issue: mobo's finnicky with memory. Had the longest time figuring out the numerous install errors I got were due to memory/mobo incompatibility. I'm put together hand-me-down components for a relative's build.

Underclocking my 2x512MB sticks for Kingston ValueRAM DDR 400 (3-3-3-8) to DDR 333 (2.5-3-3-7) did the trick. The ValueRAM's speed table has 133MHz data as well, if I had to make the drop to DDR 266. :Q

Now, here's the issue: in my sis' old computer (also a hand-me-down), there's two sticks of 512MB Mushkin, also of the "value" variety. Looking at CPUid, there's SPD data for DDR 400 (2.5-3-3-8), but that's it.

If I slap the Mushkin on my DFI RS482 board to get up to 2GB, will the Mushkin downclock appropriately to DDR 333? And if so, what timings would it use? I know I'll be stuck with a 2T command rate, but the computer won't be used for anything really overtasking - maybe photo editing.

If no one has any insight, I'll be doing this experiment Monday night - I'll let everyone know what happens. Thanks in advance!!!

 

[myocardia]

First, the RAM doesn't necessarily have to run slower, just because you're using 4 sticks. That all depends on the CPU being used. If your sister has a Venice (E3) or newer (San Diego- E4) or higher, it will run 4 sticks @ 200 Mhz just fine.

Also, SPD only applies to two sticks, if they were bought together as a set. You're most likely going to have to experiment with her RAM timings, since you're planning on using two different sets, from two different manufacturers, that use two different IC's. No matter what, though, the best you'll be able to do is the higher timings of the slowest RAM, even if the two sticks you're planning on adding are 2-2-2-5 BH-5's.

 

[PianoMan]

Thanks for the reply, myocardia!

I need to run the 1GB installed on the DFI mobo at DDR 333 since it's incompatible at DDR 400 (errors in MEMTEST 86+, no errors when used @ DDR 400 on a P4/i845 system).

The memory I'd like to put in has SPD table data @ 400, but nothing @ 333. If I stick them in (the mobo's BIOS is set for DDR 333 on the memory), will the new memory run @ 333, even if there's no SPD data? What will the mobo use for timings, in absence of the SPD table entry?

 

[myocardia]

Actually, there's an extremely good chance that you just have some of the 15 or 20 subtimings wrong, making it unstable @ 200 Mhz. Try these settings, with all four sticks installed, to be able to run them @ 200 Mhz/DDR 400 (you'll need to do this with only the two sticks that are currently in it):

DRAM Frequency (Mhz): 200/FSB 1:1
Command Per Clock (CPC): Disable (forces 2T command rate)
CAS Latency Latency (Tcl): 3
RAS# to CAS# Delay (Trcd): 3
Min RAS# active time (Tras): 8
Row Precharge Time (Trp): 3
Row Cycle Time (Trc): Auto or 15
Row refresh cyc time (Trfc): Auto or 18

Trfc should always be Trc +3. Try Auto on both first, it may work. If not, 15 & 18 should work.

Refresh period (Tref): 1560

DRAM Drive Strength: Level 6
DRAM Data Drive Strength: Level 4 (Reduce 00%)
DRAM Response Time: Normal
Idle Cycle Limit: 128 Cycles

Leave everything else @ Auto, except Vdimm. Make sure that's set to the higher of the two RAM's requirements, and don't be too surprised if it requires an extra .1v of Vdimm, since you're running 4 sticks. Most likely it will require either 2.6v or 2.7v of Vdimm, which DFI calls DRAM Voltage Control (right below the Vcore setting, most likely). And in case you were wondering, I've actually got a bit of experience with Skt 939 DFI subtimings. Okay, maybe more than a bit


To answer your question about the lack of SPD for 166 Mhz/333 DDR, it will just use the timings it has for 200 Mhz/400 DDR. But, you might as well run them all at 200 Mhz, since you now know what settings to use. BTW, you can't ever use SPD with a DFI motherboard, unless you happen to be running BH-5 or TCCD. "Normal" RAM can't handle the SPD settings that they use in their BIOS's. They expect everyone who buys their boards to be using the fastest, most expensive RAM available. Good luck.

 

[PianoMan]

Thanks again for the info! I'll try it tonight.

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Hehe...

Echoes from the movie "A Few Good Men":

"You can't handle the DFI mobo!"
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The myriad of options DFI gives for memory timings is frightening at best - I've just done some overclocking on the hand-me-down Manchester X2 3800+ (reached 2.25GHz - woohoo :roll: ), but hated delving into the 2+ pages of memory BIOS options before I got too deep into the mire of ignorance.

The info on the DFI SPD is enlightening. Which probably would explain that I didn't have any problems with the 2x1GB G.skill GBNS memory previously.

Thanks again, myocardia - I'll let you know how things turn out (or another cry for help, LOL).

 

[PianoMan]

Spent the entire time Mon night doing the software (updates, drivers, documents transfer, email transfer, etc.) - no time to do the memory.

Did just add the two sticks at 333MHz and it's running fine.

Will post when I try the settings myocardia recommends above - hopefully that'll get me to 400MHz.