On 10-07-21 11:30 AM, Doug Hughes wrote: > Yves Dorfsman wrote: >> I know that disabling hyper-threading in the BIOS improves performance >> for some type of applications. >> >> Has anybody looked into, or has experience the impact of disabling VT >> and VT-d on performance? >>
> It depends greatly upon the application. Some multi-threaded > applications get boost from having it enabled as it helps with hardware > context switching. Single-threaded monolithic applications can benefit > by not having this on and having one per core. There are many other > factors including whether the application fits in cache that affect > performance too. Are you talking about hyper-threading or VT / VT-d here? For hyper-threading, the software vendor is recommending to disable it, based on their own tests. (btw, in case it isn't obvious, I am talking about systems dedicated to one OS install only (the old fashion way), rather than VMs, or VM monitors). > I'll tell you one thing that really does seem to help, regardless. > Intel's new Turbo functionality. This is great stuff. If you're only > using 1 core of the CPU, it will disable the other 3 and overclock the > core that you are using giving you up to 400mhz speed boost. It's good > stuff. They do this by dynamically keeping track of the heat dissipation > envelope for the socket and adjusting things dynamically. It's all about > heat. (They can also power down logic components, like floating point > units, if not being used.) Yes, we have heard a lot of good things about this technology, and are enabling it. -- Yves. http://www.SollerS.ca/ xmpp:[email protected] _______________________________________________ Tech mailing list [email protected] http://lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
