Why is my bandwidth so low?

[bubbers214]

Can anyone tell me why my bandwidth is so incredibly low via Sandra? I have seen similar setups online that were getting like 7k to 8k and i only get 3.5k? I must be doing something wrong, this is my first venture into the AMD64 realm so thats got to be it.. can anyone help me figure out what it is? This is on an DFI NF4 Ultra -D btw.

Low Memory Scores Pic

 

[zakee00]

well for one, you are running single channel
two, you have a TON of crap open in the backround geez you actually benchmark with all of that open?!
three are you running 1T?
other then that im not sure...are you changing the timings in your bios or just using that windows based tweaker?
change teh timings in the BIOS like a man if you arent already, that might help
Nick

 

[bubbers214]

so does dual channel make that huge of a difference on amd64 systems?
and no I didn't benchmark with all that stuff open, i opened that stuff after benching i just kept the benchie loaded so i could SS it
yes, i am running one T and i am chaning the settings in the bios, i just put the amd tweaker there to show all my settings.

 

[zakee00]

Originally posted by: bubbers214
so does dual channel make that huge of a difference on amd64 systems?
and no I didn't benchmark with all that stuff open, i opened that stuff after benching i just kept the benchie loaded so i could SS it
yes, i am running one T and i am chaning the settings in the bios, i just put the amd tweaker there to show all my settings.

wow thats weird...and no dual chanel dosnt make that big of a difference at all, but still..
not sure what to tell you, i get about 5600MB on both tests with the rig in my sig.
sorry, and good luck,
Nick

 

[richardrds]

Originally posted by: zakee00

Originally posted by: bubbers214
so does dual channel make that huge of a difference on amd64 systems?
and no I didn't benchmark with all that stuff open, i opened that stuff after benching i just kept the benchie loaded so i could SS it
yes, i am running one T and i am chaning the settings in the bios, i just put the amd tweaker there to show all my settings.

wow thats weird...and no dual chanel dosnt make that big of a difference at all, but still..
not sure what to tell you, i get about 5600MB on both tests with the rig in my sig.
sorry, and good luck,
Nick

It is correct that Dual Channel will only perform maybe 2 to 5% better then Single Channel in applications and games. But the low Sandra mem scores are because you are using single channel. If that was a dual channel setup the sandra mem bandwidth scores would be about doubled.

For anyone doubting this with a dual channel board following is a simple test you can run.
1. Keep your mem in slots 1 and 2 (Dual Channel mode) and run Sandra Mem Bandwidth test.
2. Move the mem dimm from slot 2 to slot 3 (now you are in single channel mode) and rerun the sandra mem bandwidth test. You will see the results in step 1 are about double the reults from step 2. Makes sence, dual channel means double the bandwidth. But in the A64 world it does not mean double the performance. At the same cpu clock speed and mem timings you will only see about a 2-5% gain in performance between an A64 S754 Single Channel system and an A64 S939 Dual Channel system.

 

[bobsmith1492]

Sandra memory bandwidth scores mean nothing. Bandwidth isn't that important in most applicatins. Look at Zebo's thread at the top of the CPU/OC forum.