X2 3800 Manchester Overclocked - Lowered Memory Bandwidth?

T-LAM-C

Greetings, all, Im wondering if I can get an opinion on my overclock and an answer to a nagging and perplexing question?
My system is:

Asus A8N-E w/ BIOS 1010
Athlon64 x2 3800 @ 2500MHz (250 x 10)
HTT @ 1000 (250 x 4)
2GB (4 x 512Mb) OCZ4001024PDC-K Dual Channel @ 417 (BIOS set to 333)
eVGA e-GeForce 7600GT PCIe @ 608/815 w/ Driver 91.33
Enermax Noisetaker 420 PSU

This is a 25% OC and all voltages are normal with stock air cooling. All seems fine and stable, I am playing Ghost Recon Advanced Warfighter with no hitches or problems. The only thing that concerns me is that my memory bandwidth shows a decrease in Sisoft 2007. Was 4501/4521 at normal settings and now @ 3980/3953 with the OC. Does the BW take a hit using the memory divider? The memory seems not to want to go much further than 410/420. Thanx, any help/suggestions would be great.

lemonlime

Hi T-LAM-C,

That is most likely do to a reduction in memory frequency (from the 333 divider). Fire up CPU-Z (www.cpuid.com) to see what it is actually running at.

I wouldn't be too concerned about a reduction in memory bandwidth. The 25% CPU clockspeed increase far outweighs a small reduction in bandwidth. There may be some other things we can do to tweak your ram a bit.. Could you post your memory timings? (you can also find this from CPU-Z)

T-LAM-C

lemonlime, thanx for the reply. In CPU-Z the RAM is actually @ 417 and the timings are 2.5-3-3-5 2T, down from 2.5-3-3-7. I tried something around 2:00am this morning, I changed out the PC3200 with OCZ PC3500 from the wife's system, (1Gb 2x512). Using the same divider, 333, I raised the CPU to 2600MHz and the RAM is still showing 417 @ 2.5-3-3-6 1T with a bandwidth of 5494/5484 in SiSoft 2007. This seems promising, though I rather like the idea of 2Gb of RAM...

lemonlime

T-LAM-C wrote:

lemonlime, thanx for the reply. In CPU-Z the RAM is actually @ 417 and the timings are 2.5-3-3-5 2T, down from 2.5-3-3-7. I tried something around 2:00am this morning, I changed out the PC3200 with OCZ PC3500 from the wife's system, (1Gb 2x512). Using the same divider, 333, I raised the CPU to 2600MHz and the RAM is still showing 417 @ 2.5-3-3-6 1T with a bandwidth of 5494/5484 in SiSoft 2007. This seems promising, though I rather like the idea of 2Gb of RAM...

Yeah, when using the 1T command rate (with only 2 DIMMs) you'll get higher bandwidth. There are some nice 2GB kits (2x1GB) available, like the OCZ EB kit that will allow you to continue to operate at 1T, but I'd personally just keep what you have.

Buying new kits aside, having 2GB of memory in your system at a slightly lower memory bandwith is much more useful than 1GB of faster ram. I was in the same predicament recently, and decided just to add another 2x512s.

You may also want to increase your tRAS to 6 or 7 and re-test. There have been some tests done that suggest a 6-7 tRAS value is a bit faster than 5.

T-LAM-C

Thanx again, lemonlime, Ill give it a try. By the way, I joined F@H today under team 93, it seemed like a good thing to do. Under task manager it shoews 50% CPU usage, is that OK? Oh, great article on 939 overclocking, very helpful.

lemonlime

T-LAM-C wrote:

Thanx again, lemonlime, Ill give it a try. By the way, I joined F@H today under team 93, it seemed like a good thing to do. Under task manager it shoews 50% CPU usage, is that OK? Oh, great article on 939 overclocking, very helpful.

No problem. Glad you liked the OC article!

Thanks for joining the team! drasnor wrote a great article on F@H for dual processor machines that is applicable to dual-cores. You can find it here:

http://www.short-media.com/review.php?r=293