Intel D975XBX2 mobo and memory question

Stephen · Post by **Stephen** » Wed Dec 13, 2006 5:29 pm

I have the Intel D975XBX2 mobo, and the Intel E6700 processor is on it's way. I'm still trying to settle on memory. The mobo official specs are that it takes DDR2 800, 667, and 533 - DDR2 1000 is not listed. It also indicates it takes 1.8V and 1.9V DIMMS.

I do a lot of video editing, and moderate gaming. I'm not sure about overclodking, as I have never done it. However, I'd like to have the option to down the road if I decide to take that plunge.

So, I am trying to decide between several versions of Crucial memory. The options I'm looking at are as follows:

Crucial #CT2KIT12864AA80E, which is DDR2-800, CL=5, 1.8V.
Crucial Ballistix #BL2KIT12864AA804 - DDR2-800, 4-4-4-12, 2.2V.
Crucial Ballistix #BL2LIT12864AA1005 - DDR2-1000, 5-5-5-15, 2.2V.

The last two show higher voltage than the mobo spec sheet, and the last one shows a higher DDR2 rating than the mobo spec sheet. Does that mean these are not compatible? Or that the bios need to be tweaked for them to work and be stable?

Any feedback?

jackylman · Post by **jackylman** » Thu Dec 14, 2006 1:36 pm

Stephen wrote:The last two show higher voltage than the mobo spec sheet, and the last one shows a higher DDR2 rating than the mobo spec sheet. Does that mean these are not compatible? Or that the bios need to be tweaked for them to work and be stable?

If you wanted to get to DDR2-1000, you want to run your memory at 500MHz. The highest available multiplier on your motherboard is DDR2-800 (2:3). That means you would you have to get the FSB up to 333MHz, in which case your CPU is going to be running at 3.33GHz, which is probably about the maximum you can expect from a C2D(some samples might be better). If the CPU is not stable at that speed, you may have to raise its voltage or lower the multiplier if you don't want to raise CPU voltage.

As far as RAM voltage goes, Crucial programs less aggressive timings into the RAM's SPD(Serial Presence Detect, think of these as the 'Auto' settings) table so it will be stable enough to boot into the BIOS at 1.8V. The Ballistix DDR2-800 kit you listed probably comes programmed at CL5, so you would have to enter the BIOS, up the RAM voltage to 2.2V and then set the timings to CL4(4-4-4-12). The DDR2-1000 kit is probably programmed at DDR2-800 CL5. It may even be set to run at CL4 if it can do that on 1.8V, so in that case you would have to relax the timings in addition to bumping RAM voltage and FSB speed if you wanted to run at DDR2-100.

My recommendation? I would recommend either the 1st or 2nd one, since the 3rd one is darn expensive and probably won't give you too much more bang for the extra money you have to pay for it. Both of those 2 kits will allow you to max out your E6700 should you decide to OC it. Obviously, the second one is timed a bit tighter and will be a bit faster. Note that there are RAM kits from other manufacturers that cost a bit less.

I hope that was clear. Let me know if I can be of further assistance (I have to sleep and go to work now, but I'm sure others can help you).

Good luck

Stephen · Post by **Stephen** » Thu Dec 14, 2006 4:04 pm

Ok, I've narrowed it down to the first two choices. If I go with the 1st one listed, I assume I install the memory and I'm good to go with the bios set to default. If I go with the 2nd (the Ballistix), then you indicated it "probably comes programmed at CL5, so you would have to enter the BIOS, up the RAM voltage to 2.2V and then set the timings to CL4(4-4-4-12)." The description on the Crucial website says "DDR2 PC2-6400, 4-4-4-12...." The NewEgg website says CL-4. Is there anyway to confirm that it is programmed at CL5? If it is CL-4, does that mean I would only have to change the voltage in the bios?

Ignoring price considerations, what are the pros and cons of one versus the other - taking into account speed and stability?

Stereodude · Post by **Stereodude** » Thu Dec 14, 2006 4:19 pm

Did you check those sticks against the "Intel tested" list?

Stephen · Post by **Stephen** » Thu Dec 14, 2006 4:34 pm

Stereodude wrote:Did you check those sticks against the "Intel tested" list?

There weren't very many sticks on that list. There were some Micron ones listed, but there weren't any Crucial, Corsair, or other brands I'm interested in. I know Micron makes the Crucial sticks, but I didn't any part number on the Micron ones that corresponded to the Crucial sticks.

Stereodude · Post by **Stereodude** » Thu Dec 14, 2006 4:35 pm

Is the 975 very picky about RAM like the 965? I know there are stacks of complaints on Newegg about how picky the 965 boards are.

Stephen · Post by **Stephen** » Thu Dec 14, 2006 4:41 pm

Stereodude wrote:Is the 975 very picky about RAM like the 965? I know there are stacks of complaints on Newegg about how picky the 965 boards are.

Not that I'm aware of.

Intel D975XBX2 mobo and memory question

Intel D975XBX2 mobo and memory question

Re: Intel D975XBX2 mobo and memory question