Assymetric RAM build

[vcool]

'Lo there. I did a reinstall and decided to get some RAM.

I bought this.

Before I had this.

So I added 4 GB to an already existing set of 2GB. The timings and frequencies match, as does the voltage.

The RAM was delivered today. Gleefully, I shoved in the extra sticks and was met with the cold stare of BSOD.

Individually, the two sets work fine, and in the BIOS their freq is 1066 (533*2) plus 0.3V for advertised 1066 freq.

When I put both of them in, and set the freq to 1066 and overvoltage to 0.3, the system isn't stable. Sometimes it crashes before log in page, sometimes it crashed right after logging in. And I can't get to Windows. (using win7)

If I set the frequency to 800, it works fine (I am posting running them both but at 800).

Is this something to do with the fact they are dual channel interleaved? and if I am using both dual-channels I need to halve the frequency?

Sorry for being such a dumbass about all this, it's been a while since I rummaged on my computer.

[xoqolatl]

Your motherboard is LGA775 and is based on one of the following chipsets: P35, P45, 965P, right?
Intel officially supports two DIMMs per channel only at DDR2-800 speeds. You have a big chance of running two dimms/channel at 1066 with four identical sticks, but even that is not guaranteed.

Manually editing SPD could help you, but I don't recommend that unless you are really curious or really determined or really confident in your tweaking skills.

EDIT: If i were you, I wouldn't care. Two DIMMs per channel are faster at the same clock speed than single dimm/channel anyway. You probably wouldn't notice any difference between 800 and 1066. (Well, if I were you, I would care, it's my occupational disease, but you don't have to, really.)

[vcool]

Ha, you guessed it right. I completely forgot to specify my specs, what a dunce.

Yup, it's a P35 Gigabyte board.

So you're saying that if I order identical (same 1gb/stick) Dominators it might work? What if they are bigger as well? (there's the same pack but each stick is 2 GB)

Thanks xoqolatl, you're the man.

[xoqolatl]

Whether different sized sticks will or will not work in 2 DIMMs/channel config depends on: SPD in both kinds of sticks, how does your motherboard use the info in SPD, memory chips (things labeled D9JNM on this picture), module organization (dual rank, single rank, dual sided, one sided - if it has chips on two sides, it's dual sided and probably dual rank; most 1 gb sticks are one sided, 2 gb are two sided).
Now, there are all kinds of Dominators and the only thing they have in common is the name and sometimes the heatspreader. If your current 2x1 gb kit was two single sided modules built with for example XYZ chips, you could probably run a 2x2 gb kit of dual sided sticks built with the same chips without problems.
But your Dominators are most probably using D9GMH or GKX, which are 512 MBit density chips - that means you need 16 of them for 1 GB, so 1 GB dimm is dual sided. All current Dominators, including 2x2 kit (PN: TWIN2X4096-8500C5D) use 1 Gbit chips from other manufacturer (Micron D9xxx chips are very good, but very unique when it comes to proper SPD programming). So you would be mixing two modules each with radically different chips, different voltage, different secondary timings and drive strenghts and different module organization. I wouldn't bet on that working fine. You could probably pull it off on AMD platform, but not on P35.
Now again if I were you (disclaimer two posts up) I'd buy a second kit of G.Skills and enjoy my 8 GB memory subsystem - that should work without big problems.

Tell me if I don't make any sense.

[nub]

God damn...Gskill's DDR2 ram just keeps going up. I remember looking back at the price for that exact order about a year ago and it was $50...

[xoqolatl]

Yeah, there is a industry wide RAM and NAND flash shortage, prices for RAM and SSD drives won't be going down for several months.

[nub]

What the hell...any reason why?

[xoqolatl]

Well: Quimonda is out of business, Samsung has enormous manufacturing capacity, but is a little behing in NAND/DRAM tech, Elpida and Intel have limited capacity, Micron is struggling financially, Toshiba... I don't know about Toshiba. Most of manufacturers right now have to invest either in tech or in capacity, and it's gonna be a while until we see the return of those investments. There's no single reason for that, just a coincidence. NAND flash and DRAM prices undergo the same cycle of investments every two or so years - it's kinda natural. We had two years or so of cheap RAM and flash (SSD were expensive because technology was expensive, not flash chips), now we have a short period of not so great prices.