[OS X TeX] multi cores
gratzer at me.com
Sun Dec 13 12:13:37 EST 2009
The difference in price between the i5 and i7 is only $200.
As for TeX becoming multithreaded, who cares. As I noted before, the book I am working on is about 600 pages with hundreds of illustrations. It takes under 2 seconds to typeset. How can you improve on this and notice the difference?
On the other hand, yesterday I rendered a movie: 1 hour and 20 minutes. Unfortunately, iMovie is not multithreaded either...
On 2009-12-13, at 7:40 AM, Peter Dyballa wrote:
> Am 13.12.2009 um 12:26 schrieb Josep Maria Font:
>> According to Apple's Tech Specs page, for the 27" iMac there are, besides the Core 2 Duo processors, the following two processor configurations:
>> • 2.66GHz quad-core Intel Core i5 processor with 8MB shared L3 cache; Turbo Boost dynamic performance up to 3.2GHz
>> • 2.8GHz quad-core Intel Core i7 processor with 8MB shared L3 cache; Turbo Boost dynamic performance up to 3.46GHz; Hyper-Threading for up to eight virtual cores
> The names i5 and i7 just mean that the latter uses hyper-threading, i.e., the ability to tell the system it has twice as much cores, the i7 has one more step (5) of "Turbo Boost" mode. The elder processor is the Bloomfield and the newer ones are Lynnfield. All Lynnfield i5 and i7 and their chipsets consume less power and have a faster (built-in) memory interface (DDR3-1333 instead of DDR3-1066), including also faster access to the built-in caches (L1, L2) then their predecessors.
>> So it seems both processors have 4 real cores, and only when the software is specially desgined they simulate 8 cores (and TeXShop doesn't; or is it TeX itself ?). I'm not sure I am interpreting things right, though.
> HT (hyper-threading) is quite useful, even when you do not have software written for parallel execution. HT offers the system to do another task while this core is waiting for data to be able to continue the task it has started before. And because you have running more than 100 processes on your Mac (and almost each one is doing a small bit at any time) HT will give some advantage – almost for free (in terms of power consumption and silicon)! Safari *is* multi-threaded... ClamXav could check incoming eMails or downloads in parallel... A set of cores could deliver requested data faster to the MP3 player – or the TeX compiler. Faster spell(ing) correction...
>> Do you think there is no point (or no obvious advantage) in buying the i7 version ? I am trying to make up my mind beween the i5 and the i7 versions.
> 300 US-$ divided by three years and the hope that TeX could become parallel or the compilers might learn to understand parallelisms in the software and produce better performing code – I'd say: YES!
> When still in doubt, wait a half year! The price (for the then old model) will improve. But buy the new ones! Don't get fooled by 3.06 GHz of the rancid Core 2 Duos.
> Don't force it; get a larger hammer.
> – Anthony's Law of Force
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