800 mhz ram with 1066 cpu?

[galaxyy]

Hi All,

I'm a bit confused as to what I should set my system at.

I haven't touched my BIOS and my computer runs just fine. However, when I use CPU-Z, I see that my ram is set at:
DRAM Freq: 333.9 MHz
FSBRAM 4:5
5-5-5-15

This is not what the ram spec is (see below). Should I insert the spec values (4-4-4-12 @ 1.95V) for the ram into my BIOS or has it been set up properly since my CPU is running at 1066 while the ram is only 800?

Thanks in advance!!!

CPU: Intel Q6600 (quad core running at 1066 FSB)
Ram: Kingston Dual Channel: HKX6400D2LLK/4G (PC2-6400)

Here is a link to the datasheet for the ram:
http://www.valueram.com/datasheets/KHX6400D2LLK2_4G.pdf

But it's 4-4-4-12 @ 1.95V (800 MHz)

 

[FlorinR]

To find out the freq. of your memory (x) do the math:

FSB 4
------- = -------
DRAM 5


Where, the FSB is your's: 1066/4=266Mhz (bus speed of Q6600), so:
(266*5)/4=333MHz
But the memory is off course DDR=Double data rate, meaning: is operating at 2*DRAM freq: 2*333=667Mhz.

For personal self esteam you can change the 4/5 ratio in BIOS so that CPU-Z to show 400Mhz, meaning that memory freq will be 2*400=800mhz.

Hope that you get it

 

[galaxyy]

That's a great reply and fills in the gaps in my knowledge here. However, it's still unclear to me what I should have my settings at. Should I drop my ram down to the 4-4-4-12 or is it running at 5-5-5-15 because it is running at 333 instead of 400?

 

[ausch30]

Run CPUZ and click the SPD tab, it should give you a screen like this

Although your RAM was sold as DDR2 800 there should be a few different settings including 667 (keep in mind that 333 in CPUZ is 667) which will run 1:1 with your CPU.

 

[galaxyy]

Ah ok, so I guess then based on what I see:

That I'm already using 333 (says under the memory tag). So with m 1066 CPU, I guess I'm stuck using the worse latency/etc (5-5-5-15) than the rated 4-4-4-12....

Can someone confirm please that I must match the bus speed of the CPU and the ram? Or can I change the FSBRAM ratio? 1:1 would allow me to run my ram at 266 MHz as shown above...is this the best option for me? I know I'm asking a lot, I appreciate any help that anyone is willing to give

 

[ausch30]

You don't need to run 1:1 but Intel chips have a slight performance increase with that ratio. You could try increasing the memory voltage and reducing the timings but considering it's value ram I'm not sure how much overclocking headroom it would have.

Edit: I actually mis read your first post, I thought you were overclocking and needed your RAM at 333 to run 1:1. 266 is what you want, it is DDR2 533 and would run 1:1 with your 1066 FSB.

 

[galaxyy]

Actually, I have DDR2-800 ram...and it's Kingston HyperX dual channel ram (not that I know if that truly changes the overclocking possibilities).

So I'm guessing that what I really want is 1:1 FSB to RAM ratio, so I want my ram at 266? Is 1:1 a good general rule-of-thumb?

 

[ausch30]

lol, sorry I need to pay attention better before I start typing.

just use the 266 4-4-4-12. 1:1 really depends on your system and your RAM. If your using a different ratio and running only slightly faster than you would using a 1:1 ratio you might get slightly lower performance. The whole point is so that your CPU and/or RAM aren't wasting clocks waiting for the other to be ready.