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List:       opensolaris-discuss
Subject:    Re: [osol-discuss] Another [OT] Hardware Post
From:       Erik Trimble <erik.trimble () oracle ! com>
Date:       2011-02-25 16:56:02
Message-ID: 4D67DF22.2090209 () oracle ! com
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On 2/25/2011 1:23 AM, Orvar Korvar wrote:
> Regarding i7 uses too much power, and i5 is better - i5 doesnt suit my needs. I \
> want plenty of CPU power when I need to and it does not matter if the cpu sucks \
> much power when I am doing heavy calculations. The rest of the time, when I dont do \
> heavy calculations, I want it to idle at very low wattage. I basically want a cpu \
> with low wattage in idle and when I surf the web. When I need to, I want to have \
> plenty of power and in that case it it allowed to suck much wattage. 
> I would not like to have a weak cpu, and when I need to do some heavy work, I need \
> to switch to another PC with a beefy CPU. Then I need two PC, one for web surf etc \
> and one for heavy work. I want one PC, that has low power wattage in idle and surf \
> the web, and plenty of muscles when the need rises. I suspect Sandybridge will idle \
> at 50W. Or maybe I wait for Ivy bridge...

Like I said before, modern CPUs idle down quite far when under low load. 
The Clarksdale i5, all SandyBridges (i5 & i7), Athlon II X4, and even 
Phenom II X6, will shut down cores that aren't being used. So, for web 
surfing, you're likely idling half of the CPU, a 65W TDP CPU should run 
at 30W or less.  That's ALL the current-gen CPUs.

i7 single-threaded performance isn't really any better than i5, even on 
SandyBridge-cores. SandyBridge single-thread is pretty much the same as 
Clarksdale single-thread, and both are 10-15% faster than Athlon/Phenom 
single-thread.   Exact performance depends on your application, as both 
the i7 and Phenoms have significant L3 cache which can really help 
certain apps (and be totally worthless for others).

Realistically, an i7 will be faster than an i5 on heavy memory-access 
applications (they have a faster/wider memory bus). On low-memory access 
stuff, an i7 won't be noticeably faster than an i5.  Also, an i7's 
HyperThreading can be both a bane and a boon. For certain apps, having 
more threads available is great; however, you can easily get into cache 
thrashing with HyperThreading, so it's really best used when you have a 
single app that wants 80% of the threads, not 10 apps all with one 
thread each.  In the later case, you'd be better off with a Phenom II X6 
(or, shutting off Hyperthreading, but then again, why not get an i5 in 
that case?).   (I work in the Java VM group, and see lots of issues 
around getting the best performance with HyperThreading on - how to 
maximize your performance without stepping in the "death zones" where it 
tanks.)


> 
> Regarding the 3D driver for Sandybridge. Yesterday I got a mail from someone at \
> Oracle writing: "We are planning on integrating 3D support for Sandybridge as soon \
> as we get KMS support in." Thank you for this information! :o)

[Obdisclaimer: I do not speak for Oracle, nor have any privileged inside 
info about this]

Also, do be aware that Solaris 11 Express is almost certainly required 
for this support (whenever it shows up); it's unlikely to be made 
available to the IllumOS/OpenIndiana folks.  So, you'll either (a) have 
to buy a support contract for your PC to get it ($1000 or so), or (b) 
wait for the next release of Solaris 11 Express (maybe 6 months or more?)


-- 
Erik Trimble
Java System Support
Mailstop:  usca22-123
Phone:  x17195
Santa Clara, CA

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