Xeon rack systems-question

[Smalerbi]

We just had a small rack mounted render farm built (4 machines – Dual 3.2 Xeons) and tried it out for the first time and I had a question. The first thing we noticed was high pitch whining from the processors during rendering. It almost sounded like a tea kettle boiling. The other thing we found odd was the lack of performance. We also use some of our workstations for render nodes and they are only dual 2.8 Xeons. Oddly enough, the 2.8’s are faster and quieter. When the work stations are rendering, there is no difference in sound from rendering or sitting idle. Has anyone had this issue with there rack mounted Xeon systems.

Thanks,

Scott.

[joconnell]

Well, one thing that can happen is some computers use fans to keep the cpus or case at a constant temperature and when the computer heats up the fans speed themselves up to more aggressively cool the system. Once the heat has been removed they slow down again to keep quiet. For a render farm though you'd ideally keep the fans turned up to full rpm all of the time and have the machines in a different room. Rackmount cases are harder to cool than towers too. It might be something like dust getting into the fans and clogging them or possibly thermal paste not working correctly and your system complaining - my BOXX system has a fit any time the cpus start to overheat and squeals like a wee piggy to let me know there something wrong - normally it's taking the case off and cleaning the fans a bit. Seems unlikely in a brand new system though.

Have you got anything to monitor the temp of the cpus inside of windows? Might be worth keeping an eye. Xeons will slow themselves down when they start to overheat as a protective measure too...

[Smalerbi]

Have you got anything to monitor the temp of the cpus inside of windows? Might be worth keeping an eye. Xeons will slow themselves down when they start to overheat as a protective measure too...[/quote]


That would seem to make sense. I had a similar theory. One of the things I noticed during the rendering is the cycling of the fans. When the renderings first started out, there is very little geometry in the scene; sky elements etc and the fans are quiet. As the buckets move downward, the geometry gets heavier and that’s when the system starts to squeal like a stuck pig. Now the other thing, I was very surprised to see a drastic performance difference from each machine. See attachment for example. The DR machines are a couple of work stations rendering and the RS systems are the rendering slaves…………see the performance difference. It is enough to make you want to open up a major artery. Time to send this back for some tower systems.

Thanks for the feedback

[Erik de Graaf]

Hi,

All i can say is that we also have 5 rackmount dell systems and they perform very good, can't compare to a dual cpu workstation though. But the rendertimes are all alike and the noise is something you have to live with i quess, we have them in a separate room(server room). We use the poweredge 1750 and 1850.

If you open them up you can see a series of small fans wich go like there about to take off with the entire servercase.

So i guess cooling is very important, can you measure the temparature of the room they are in?

Good luck,

Erik