RAM says to run it at 2.1v to work at 4-4-4-12 settings. PC crashes at 2.048v...

[Deja Q]

Might I have a faulty RAM module, or must I use the next voltage setting to get these to run at advertised specs?

Corsair TWIN2X4096-6400C4DHX. Two of them; totaling 8GB.

They seem to work at their programmed SPD rate (5-5-5-18, 1.8v) and perform better than the g.skill RAM I had before... which is bothersome; if rated for 4-4-4-12 @ 2.1v, why weren't those specs programmed instead?

I will run Vista's RAM diagnostics overnight to be sure I don't have a faulty module, but I digress: They say 2.1v, so is 2.048v truly too low? (the next step would raise it to 2.148v, which is pushing things a tad...)

[RoyGBiv]

1. If the stick is good ...

It could very well be the motherboard ... not that there's anything specific wrong with the motherboard, just that matching memory with a mobo to perform optimally can be a tricky exercise.

[Deja Q]

2. After looking up various websites, I stumbled on this:

http://www.tomshardware.com/forum/248026-30-corsair-6400c4

Same issue encountered by other folks; and the concensus is to not fiddle: if benchmarks from both before and after setting the parameters remained similar, there's no point in the risk...

You're right; it can be very tricky an exercise. :D

[Tandalayo_Scheisskopf]

3. I have found...

That when it comes to RAM, rated voltage is the only way. If it says 2.1 volts, then anything less is trouble. Anything more? Well, make sure air flow across the heat sinks is good.

[Deja Q]

4. I'll give that a try, but a question

I know that, for AMD, using all 4 RAM slots leads to a performance dip.

Is it possible that, using all 4 slots in an Intel rig (socket 775, Q6600 CPU) that there could be a performance issue here?

Right now I am noticing a very high bandwidth... crippled by high latency, according to the sisoft benchmarks...

[Tandalayo_Scheisskopf]

5. Are you remembering...

That DDR2 means doubled latencies as well? So 5-5-5-15 is the same as 2.5-2.5-2.5-7.5

And SiSoft does seem to make some assertions that are not entirely accurate.

[Deja Q]

6. Not until you reminded me.

:)

I did reconfig my RAM to 667MHz speed (1:1 ratio) and it's running stable at 4-4-4-12 @ 2.0v. I might try 3-3-3-8, some have reported success... or o/c the CPU to 3.6GHz (400MHz FSB) so I can run the RAM at 800MHz. The CPU temp remains at 32C, which is nice... I just don't want to blow up the CPU... :D

Right now the bandwidth (at 667) is 51000mb/s ((at 1000mhz, it was 59000mb/s)), but everything loads and runs MUCH faster, it's impossible to believe, but true.

http://www.corsair.com/configurator/product_results.aspx?id=205189
(nice place to check compatibility)