Hyperthreading

[taltamir]

forget hyperthreading... (well, don't forget it, it will be good for you, but in addition to it.).
Nehalem was designed to be a server chip through and through... aka it will be exactly what you need for VM ware. While it has negligible to none to NEGATIVE performance increase for games, it should be significantly faster per clock for you.

 

[IntelUser2000]

are these figures with turbo mode on or off?

Turbo mode at default is at best 8% increase that corresponds to 3.46/3.2. Most likely its half that.

Hyperthreading in VM's provides mixed results. Most of the results are generally opionion and based on the workload.

Going off of basic test any software that sets affinity you will notice weird, sometimes buggy results. If you are using quite a bit of the CPU on any of the VM's it is best to turn off HT. If you are just launching 6-8 VM's with very low cpu activity then HT is a plus.

That was true because the P4 architecture was in a way made SMT really bad in some cases. Nehalem has less of the flaws.

+1

That's exactly the point AT made in their review, hyperthreading on P4 was hobbled by the low throughput of the processor (single core, remember?). CPUs have gotten much "smarter" since then and can juggle the tasks more effectively among different cores. And the 8MB L3 cache doesn't hurt, either!

You guys wanna look back to my post here, substantial amount of the multi-threaded performance increase also comes from the core changes: http://forums.anandtech.com/me...erthread=y&STARTPAGE=3

Xbitlabs

Core i7-965 SMT off/Turbo off vs Core 2 Quad QX9770: http://www.xbitlabs.com/articl...-core-i7_10.html#sect0

There are significant advantages to be had by CPU core changes alone, average benefit from non-SMT changes and SMT changes(not including PCMark and 3DMark) shows 8% each.

Tomshardware

Core i7-965 SMT on vs Core 2 Quad QX9770:
http://www.tomshardware.com/re...7-Nehalem,2057-11.html

Core i7-965 SMT off/on comparison:
http://www.tomshardware.com/re...7-Nehalem,2057-12.html

Substantial amount of performance comes from core changes.

Cinebench shows no difference because its a real world app that doesn't reflect majority of other real world apps.

Indifferent to cache change(<1% difference), when lots of apps will be affected by it
http://www.nordichardware.com/.../?skrivelse=514&page=5