Running 2gig x 4 in double dual channel?

[blue4paper]

I've read that this is possible, to run 4 sticks of 2 gig for a total of 8gig in dual channel mode, is this correct?

Also, I've also read that when you fill up all memory slots that you lose 1t command rate and it drops to 2t.

I've looked at the benchmark results and the difference in performance seems quite noticeable. However, all the forum posts I've read on this matter is 2007 and below and they said this was a result because the motherboards just couldn't handle all slots at 1t command rate.

Does this still apply?

System specs:



Thanks,
Blue

 

[Slaymate]

Unlike those older reports you were reading, the memory controller is built into your cpu and not the motherboard. So those article really don't apply anymore. The only real issue concerning your motherboard would be the bios and that is usually updated a few times to improve performance and stability as more and more consumers report problems.

A lot of things can cause your system to require different memory settings. Because the memory controller is built into the cpu "Heat" can cause major issues. The Quality and Speed of your memory can cause problems. If your overclocking any weakness can affect any component.

My office PC, i7 920 @ 4GHz has 6x2GB of memory running at 1600 MHZ 7-7-7-21-1T so I'm sure your system should be able to run at it's specified settings if you have a quality cooling system and quality components.

 

[blue4paper]

Oh, so running 4 sticks of identical memory @ tighter timings will cause more heat than just 2 sticks of overclocked memory? I guess that makes sense because there is more stress on the memory controller.

Currently my ram is rated at 7-7-7-21 @ 1333mhz, but the bios automatically sets it to 9-9-9-24. However, I managed to bring mine down to 7-8-7-21 @ 1600mhz, so I supposed having 4 sticks all running at those latencies and frequencies would 'double?' the stress?

 

[Slaymate]

I don't think it will "double" the stress, but it will increase it, how much we just don't know. If your temps are good you might need to up the DRAM Voltage and/or the IMC (Integrated Memory Controller) Voltage. The IMC Voltage is also call the CPU VTT on some mobo's.

 

[blue4paper]

I see. I'm already overclocked to 3.8 ghz @ 1.23v with my i5 and with intelburntest i get temps of low 70's. However, intelburntest is the only program so far that's pushed my cpu to those temps. General gaming it doesn't go beyond 65. So I suppose adding 2 more sticks could pose a problem. I guess the best way to find out is to slap in two more sticks and see the results.

I'm curious why you said "if your temps are good, raise the dram/vtt voltages." Wouldn't checking for stability be more of a reason to raise the volts?

Thanks,
blue

 

[Slaymate]

If you have issues you can try raising a few voltages for stability if your temperatures are good. If your already in the 70's running Intel Burn Test or LinX you don't have much headroom.

There was a time not that long ago when adjusting your system for maximum performance meant aquiring the lowest possible latencies, even at the expense of a few MHz in cpu speed. This is no longer true. With the memory controller built into the cpu we no longer have the bottleneck associated with the older technology. Instead we have a wider direct path between the cpu and memory controller which results in fast access to a tremendous amount of bandwidth. So, while we still want the fastest possible latencies, we no longer have to sacifice any cpu MHz's. I would rather run at higher latencies at 4.0 GHz than slightly lower latencies at 3.9 GHz.