Memory Speed Question

[tnt118]

OK -- maybe I just haven't had my coffee yet and something isn't clicking, but I wanted to ask a quick question about memory speed.

(About every six months I try to go through and make sure all my drivers, etc, are up to date. I'm generally pretty good understanding the finer points of computer builds, but I don't deal with it frequently enough to consider myself an expert).

I have an ASUS P7P55D Deluxe motherboard - [4 x DIMM, Max. 16 GB, DDR3 2200(O.C.)*/1600/1333 Memory]. Memory is Corsair Dominator DDR3 [240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)].

CPU-Z is reporting my DRAM Frequency at 668.7MHz. I noticed in the BIOS that DRAM Frequency is set to auto, and not forced to 1600. So, shouldn't the frequency be running at 800MHz... I mean, shouldn't I be forcing 1600?

Appreciate the help and advice!

 

[*kjm]

I would think it's because your system is down steping because you are not running anything that needs the full system. Click on SPD and it should show full memory speed on the right side. Your system will ramp up to that when it is needed..... power savings.

 

[nipplefish]

No, the board defaults to 1333 MHz memory speed. DDR stands for Double Data Rate, so 2x667MHz = 1333. You'll have to manually set it if you want it to run at 1600. What CPU do you have?

 

[tnt118]

What CPU do you have?

i7 860

Looks like that is spec'ed for DDR3 1066/1333.. will that be the bottleneck or is it still OK to force 1600?

Also, the specs of the RAM say the timing should be 8-8-8-24, but the auto settings of the motherboard have it at 9-9-9-24. Not sure if I should change this?

 

[nipplefish]

Yeah, you can force 1600 no problem, that will just up your FSB: DRAM ratio to 2:12. I'm pretty sure my board has the same BIOS as yours. Are you overclocking at all? If so you'll probably want to set it to 1333, since the DRAM speed is determined by the BCLK (133MHz default) multiplied by the ratio. Upping the BCLK will increase the DRAM speed.

As for the timings, yeah, you can change the timings manually. It should work fine as long as the RAM is spec'd for it. Worst that can happen is you'll get a bluescreen and have to reboot.

 

[Ben90]

The reason why it is defaulting to 667 (DDR-1333) is because that is the highest the 860 "supports" in dual channel mode. Unofficially DDR-1600 in dual channel will work everytime, but the gains are minimal.

If you absolutely must have all the IPC your processor can handle, you can always manually set your RAM to DDR-1600 or higher but unless your overclocking, I doubt the gains are worth it.

Judging by your uncore it looks like you not overclocking. Most likely you can select a higher memory multiplier and not have to worry about the bclock messing up other things. Remember that this will technically "overclock" your memory controller but it can handle it.

 

[Yellowbeard]

I suggest you clear the BIOS and then enable the XPM profile. On that board with the CPU and RAM you have, this should set the settings you need automatically.