bandwitdh

[euphoria651]

hey, can anyone tell me the memory bandwidth of my system? i have a 2500+ barton and 2*256mb DDR400 in dual channel (total 512mb)? thanks

Judge me all you want; just keep the verdict to yourself!!!

 

[darko21]

What is your FSB set to? is it running in sync.

What timmings are you using?

What program are you running to check it. Their is theoretical and what you can expect.

I think the theoretical memmory bandwidth for the nforce at ddr 400 dual chan in sync is 6.4 .... but that's a bit of a guess from me so someone please fill in the blanks if i'm wrong.

If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.

 

[Schmide]

Although the chipset has a bandwidth close to (2x64x400)/8=6.4gbs. The processor has only a single (64x400)/8=3.2gbs. For the most part you only get about 80-90%=2.8gbs of that due to latency and other penalties. Since the 2500+ front side bus only runs at 333mhz your looking at 2.6gbs or actual 2.3gbs throughput.

Dichromatic for your viewing plesure...

 

[darko21]

Thanks Schmide,

You are one of the best posters on this site.

What does that work out to if using 400 ddr @ 400 sync. Sorry I'm to lazy to do the math and I'd probably screw up the math anyway.

If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.

 

[darko21]

Sorry re read the post so 2.8gbs is the max in this case?

If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.

 

[endyen]

If you want to know the theoretical bandwidth of a piece of DDR ram, look at the name. DDR 333 is called pc2700 and has a bandwidth of 2.7 Gbps. DDR 266 is called pc2100 and has a bandwidth of 2.1 Gb/s. It's pc designation is eqal to its theoretical bandwidth in Mb/s.

 

[darko21]

Makes sense to me but what about the Dual channel part. I suppose thats how they get 6.4 ...So what what could one expect with dual channel ddr 400 in sync. is it 3.2 cause of the cpu or does the dual channel advance it further. does the dual channel elimiate some of the other penalties bumping theoretical to pratical 3.2+ or more with good timmings?

If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.

 

[endyen]

With the Amds ya it just increases the effective to close to theoretical. intel uses two seperate pathways so the bandwidth is addative, but not as effective.

 

[darko21]

Theoretical 6.4 or theoretical 3.2. I ask because of schimdies statment on the limitations of the CPU.

I am assuming Dual channel closes the gap closer to 3.2 in pratical.

If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.

 

[endyen]

Yes the theoretical for Amd is 3.2, Ive seen effective testing as high as 3 (sandra).