Low Memory Bandwidth

Bobendren · Post by **Bobendren** » 16 Apr 2005, 00:23

Setup:

Gigabyte 865G mobo
2x Kingmax 512 DDR500 @ddr400(for the moment) CL2.5, dual channel
2.4c Northwood

Problem:

Why is my score not higher?

Hill · Post by **Hill** » 16 Apr 2005, 07:32

Well for one they are running a CAS latency of 2 and you a CAS latency of 2.5. Also there may be slight differnces in the architecture of the different Mobo's.

All these little things add up.

Soap · Post by **Soap** » 16 Apr 2005, 09:53

If you achieve 4180MB/s, you can be sure that you're running Dual Channel, as a normal DDR400 module would only allow up to 3200MB/s transfer. If you're using a 865G, I'd recommend if applicable to use an external graphics card. Also remember that a lot of board manufacturer's have (unofficially) integrated PAT into the 865PE, which the 865G does not have.

VoodooProphetII · Post by **VoodooProphetII** » 16 Apr 2005, 10:17

I'm not sure about Intel mobo's, but if you could disable the T2 or enable T1 it would increase the bandwidth by a fair amount.

Jasonhk · Post by **Jasonhk** » 16 Apr 2005, 10:29

There is nothing wrong with that Bandwidth....It's standard for intels to be slightly lower then Socker 939 setups...My highest i got overclocked was 8005Mb/Sec

VoodooProphetII · Post by **VoodooProphetII** » 16 Apr 2005, 11:10

Jasonhk, yours was on a 939 mobo and Athlon 64, and with low latency like 2 2 2 5 at most likely 500Mhz or so, I'm just talking out of head here. I managed only around 6800 with Trancend standard DDR400 clocked at 460Mhz and latency at 2.5 3 3 6.

aXe · Post by **aXe** » 16 Apr 2005, 19:49

That looks normal from the specs.

Bobendren · Post by **Bobendren** » 16 Apr 2005, 20:50

Hill wrote:Well for one they are running a CAS latency of 2 and you a CAS latency of 2.5.

At CL2.5 i got only about 30mb/s faster than CL3, so i don't see CL2 making that big of a difference.

If you achieve 4180MB/s, you can be sure that you're running Dual Channel

Ja i checked that already by switching the one of the dimms to a different slot. Only got in the 2900's, pretty weak hey?

I'm not sure about Intel mobo's, but if you could disable the T2 or enable T1 it would increase the bandwidth by a fair amount.

er..i've got a gigabyte mobo, didn't find anything in the bios about T1 or T2 though.

It's standard for intels to be slightly lower then Socker 939 setups

but i'm not comparing it to the 939 socket! i'm rating it against practically the same setup.

anyways thanks for all the replies

. would updating the bios aid me on my quest for more bandwidth? currently i have version f4, f5 is available, but i'm worried i'll kill my pc.

MrBean · Post by **MrBean** » 17 Apr 2005, 11:49

If you want to compare, you will have to make sure it is against a P4 2.4C as well, with CL2.5-3-3-8 or something.

CL2-2-2-5 will show significant higher scores when paired with a faster cpu.

Your scores seems on par, maybe a tad low, I would have thought 4300-4400 for that setup. But, still in the ballpark anyway.

Br,
MrBean.

Jasonhk · Post by **Jasonhk** » 17 Apr 2005, 14:46

The reason why i was saying 939 is because AMD's score high in memory bandwidth, so yoy might of thought your score was bad but its the norm for intels like yours, soz for misunderstanding a bit

Bobendren · Post by **Bobendren** » 23 Apr 2005, 19:49

after ocing the memory to ddr500 and a few BIOS tweaks i got this:

i am over stoked about the result, 2.4 now runs at 3.0Ghz too.

timings are still 3-4-4-8 though, so a marginal inprovement could still be achieved.

just out of curiosity i benched the ram at ddr400 with the bios tweaks on this time and got above 4500. so that was all i originally needed to do. PSB Parking, Command Per Clock, Fast Chip Select and Dynamic Paging Mode were the tweaks i'm refering to, if you're wondering.

i ran prime95 for 2 and 1/2 hours and no errors. i should have left it a while longer but i wanted to post this. so there it is.

Soap · Post by **Soap** » 23 Apr 2005, 20:27

Jasonhk wrote:The reason why i was saying 939 is because AMD's score high in memory bandwidth, so yoy might of thought your score was bad but its the norm for intels like yours, soz for misunderstanding a bit

That is primarily only because the Athlon64 has an integrated memory controller and doesn't rely on the northbridge to take over the task of memory management.

You know, I wouldn't get too much caught up with bandwidth. We're talking about 4GB/s. Imagine, that's a 40GB drive filled in 10 seconds, or even less if you think that manufacturer's only calculate in 1000 and not 1024.