[Beowulf] Opinions of Hyper-threading?

[John Hearns]

On Wed, 2008-02-27 at 23:30 -0800, Bill Broadley wrote:

> 
> I don't see any particular reason why memory bandwidth can go through a full 
> doublings in the near future if there was a market for it, last I checked 
> nvidia was doing pretty well ;-)
> 
> [1] Sorry to use marketing bandwidth, I've not seen stream numbers for CUDA
>      yet.  I hope to work on one though.  If anyone has numbers please speak
>      up.

Some numbers here:

http://forums.nvidia.com/index.php?showtopic=52686


Running this on my 8600 card I get:

STREAM Benchmark implementation in CUDA
 Array size (single precision)=2000000
 using 128 threads per block, 15625 blocks
Function      Rate (MB/s)   Avg time     Min time     Max time
Copy:      291777.6696       0.0001       0.0001       0.0001
Scale:     291777.6696       0.0001       0.0001       0.0001
Add:       437666.5043       0.0001       0.0001       0.0001
Triad:     437666.5043       0.0001       0.0001       0.0001


All the 0.0001 don't look right to me, but its 8:30 here and I should
get on with the day job.