Tuesday, December 16, 2008

Windows CCS Cluster Upgrade

Recently the Windows CCS Cluster of the RRZE got a small upgrade.

One of the initial nodes rejoined the cluster and there are now 28 Opteron Cores available again.
Due to the usage of CFD for production runs, the user home was recently upgraded and the quota was extended to 10 GB per user.
Furthermore for special purposes and a limited amount of time there is an extra project home available with up to 120 GB space for extensive usage.

Monday, December 15, 2008

PCI express revisited

Test results with the new generation, i.e. GT 200 based and PCIe Generation 2.0 with doubled performance, show that general naive implemented copys do not get any speedups.
Blocked copys however, climb up to 4.5 GB/s when writing data to GPU memory.
Data copy back to the host is still relatively low at 2 GB/s.

pcix bandwidth measurements 8800 gtx vs. gtx 280

Link to first article

Monday, December 8, 2008

Fast Network, Fast disconnects (Linksys WRT610N )

Fast Network, Fast disconnects (Linksys WRT610N )
Looking forward to fast streaming HD Media over my new wireless router (WRT610N) I got into serious trouble on having a stable connection at all.

Having my network set up for WPA2 and TKIP for compatibility reasons, I got random disconnects of the whole 5 GHz band, while 2.4 GHz performed flawlessly. Searching the internet I stumbled across some serious accusations, that the WRT610N is a flawed design and overheats a lot.
Whether this is right or not I cannot say for sure, however I expected much more from Linksys and a home premium line product.

Searching a little more I came across another users experience that a change from the TKIP encryption to AES solved the problem of occuring disconnects.

And voila the problems seems to be solved.

So for everyone who can live with an AES only encryption on the 5 GHz 11N band and TKIP or AES on the 2.4 GHz 11g band the router is a perfect catch in both performance and appearance.