AMD Athlon II X4 620, 4x 2.60GHz, boxed - for 83 €
 

The [URL="http://geizhals.at/deutschland/a453235.html"]AMD Athlon II X4 620, 4x 2.60GHz, boxed[/URL] will be released soon for around 83 Euro. With a decent but not expensive mainboard could it be a decent Prime95 computer?!

[quote=joblack;187156]The [URL="http://geizhals.at/deutschland/a453235.html"]AMD Athlon II X4 620, 4x 2.60GHz, boxed[/URL] will be released soon for around 83 Euro. With a decent but not expensive mainboard could it be a decent Prime95 computer?![/quote]
It seems to be a cheaper version of the Phenom II. The only difference i can find is it has twice as much L2 cache and no L3 cache. This might even be a better solution for some programs as L2 cache is faster than L3 cache.

[quote=henryzz;187158]It seems to be a cheaper version of the Phenom II. The only difference i can find is it has twice as much L2 cache and no L3 cache. This might even be a better solution for some programs as L2 cache is faster than L3 cache.[/quote]

The question is how will it perform mainly for prime95 (the other tasks it should do are all server stuff (webserver, scripts, ...) where high speed isn't the main purpose ...

Btw. the L3 cache doesn't slow down some programs (anyway it's mostly faster than the main memory) - its complete transparent ...

Hm, the Athlon II is supposed to be 1024 KiB L2 cache per core yet that site says 4 * 512 KiB L2 cache. A simple mistake I hope.

Anyway, the i7 CPUs use the L3 cache to share data between cores, I'm not sure if Phenom II CPUs do that also, if they didn't then the lack of an L3 cache probably won't have much of an effect. I believe they always use the hypertransport bus to share data. The increase of L2 cache though should allow for greater performance at higher FFT lengths.

Overall though, the CPU is dropping from 8 MiB L2+L3 cache to 4 MiB L2 cache, so clearly some applications will not perform as well, I don't believe P95 is one of those applications as it is not optimised to use L3 cache.

As to how well it will do, I don't suppose the performance will be too much different to a similarly clocked Phenom II, but with the reduced cache they will be cheaper, and from what I read the Phenom IIs are quite overclockable.

Check out the Phenom II 710 and 810 on here:
[url]http://www.mersenne.org/report_benchmarks/?32bit=1&64bit=1&exover=1&exbad=1&speed_lo=2595&speed_hi=2605&min_num=5&exp_date=&B1=Get+Benchmarks[/url]

And here's some estimated throughput per day on a 2.6 GHz Phenom II:
[url]http://mersenne-aries.sili.net/throughput.php?cpu=AMD+Phenom%28tm%29+II+X4+940+Processor|512|6144&mhz=2600[/url]

[quote=lavalamp;187275]Hm, the Athlon II is supposed to be 1024 KiB L2 cache per core yet that site says 4 * 512 KiB L2 cache. A simple mistake I hope.

512 KiB is right - it's one of the cheapest quad cores available. It's clear that more Cache is better but then the price also rises. The question is if this cpu has the best performance / price ratio to run prime95 ...

Hm, seems it's only the dual core Athlon II CPUs that have 1024 KiB L2 cache per core, that's a shame. If it had been that way for quad cores too then it would have been an absolute bargain chip.

It should perform very similarly to the Phenom II CPUs then, perhaps slightly worse as other programs requiring CPU use won't be able to store data in the L3 cache so there will be more waiting involved while they get it from the RAM.