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Main => Software Forum => Topic started by: speedklz on November 18, 2009, 10:33:32 am

Title: Single core verses dual core
Post by: speedklz on November 18, 2009, 10:33:32 am
I have two machins right now that I am contemplating putting in my cab. Both are AMD Athlons X64 with XP64 installed. Now Am I going to be able to run anything different if I use the duel core verses the single core if both are running 2.8 with 1 gig ram?
Title: Re: Single core verses dual core
Post by: drventure on November 18, 2009, 11:35:37 am
As far as I know, mame only uses a single core, so dual core won't buy you anything there, though if there's other games you want to run, it might help.
Title: Re: Single core verses dual core
Post by: speedklz on November 18, 2009, 11:52:37 am
No just trying to get some of the elusive ones to play well.. I love Blitz 99 and some of the better fighting one.. But the sound just isnt smooth...  Wonder if the old smoothmame patch helps out any..
Title: Re: Single core verses dual core
Post by: massive88 on November 18, 2009, 12:06:51 pm
As far as I know, mame only uses a single core, so dual core won't buy you anything there, though if there's other games you want to run, it might help.

Mame can be set to multithread, but it doesnt help a whole heck of a lot.  Its about a 5% performance increase across the board after toggling multithreading (using 2 cores).

Speedklz - if you have both boxes up and running, just do a few benchmark runs with Mame and see for yourself if theres any appreciable difference.
Title: Re: Single core verses dual core
Post by: speedklz on November 18, 2009, 12:27:48 pm
Yea, I am currently compililing a 64 version and a 64 duel core version to do just that... I was hoping someone had tried before.
Title: Re: Single core verses dual core
Post by: massive88 on November 18, 2009, 12:32:45 pm
Yea, I am currently compililing a 64 version and a 64 duel core version to do just that... I was hoping someone had tried before.

Well like I said, its generally about a 5% increase in speed.  But mame can vary a bunch from driver to driver, so for any particular game it could be better or worse.

Dual core may also get more utilization in future builds, though its hard to say.
Title: Re: Single core verses dual core
Post by: u_rebelscum on November 18, 2009, 01:21:45 pm
Yea, I am currently compililing a 64 version and a 64 duel core version to do just that... I was hoping someone had tried before.

Well like I said, its generally about a 5% increase in speed.  But mame can vary a bunch from driver to driver, so for any particular game it could be better or worse.

Yeah, I've heard a few games do get a nice boost, but they're the exception usually.  At least as of a few versions ago.

One thing I've been wondering about is Intel's i7 & i5 "turbo" feature (http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3641).  If all cores are used, the chip runs at the stated speed, but as fewer cores are used, the chip is able to run at faster speeds automatically.  For an app like mame, that can use multiple threads/cores, but only to a small boost, would it be better to force using less cores to great a higher turbo?
Title: Re: Single core verses dual core
Post by: massive88 on November 18, 2009, 01:53:52 pm
Yeah, I've heard a few games do get a nice boost, but they're the exception usually.  At least as of a few versions ago.

One thing I've been wondering about is Intel's i7 & i5 "turbo" feature (http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3641).  If all cores are used, the chip runs at the stated speed, but as fewer cores are used, the chip is able to run at faster speeds automatically.  For an app like mame, that can use multiple threads/cores, but only to a small boost, would it be better to force using less cores to great a higher turbo?

Id love to see some people run some benchmarks.  I havent really seen any i7 i5 numbers as compared to the core2.
Title: Re: Single core verses dual core
Post by: atomikbohm on November 19, 2009, 02:05:18 pm
I have an I7 920 that I'd be happy to do some benchmarking if someone can walk me though how to do it in Mame.  The last time I did bench marking was on an AMD socket 7 series and I don't remember anything other than my immediate need to but a new computer  :badmood:

On a somewhat related note ... the I7 chips have 4 cores with hyperthreading windows sees it at effectively 8 cores what are the best performance options to use when compiling Mame for the newer processors?  Are the dual and quad core opti's for specific architecture (i.e. core 2 duo) or for generic 2 or 4 core processors (p4, core 2, core 2 duo, core 2 quad, I7)?
Title: Re: Single core verses dual core
Post by: massive88 on November 19, 2009, 02:14:36 pm
For benchmarking I made a batch file with the following:

mame -noautoframeskip -frameskip 0 -seconds_to_run 100 -nothrottle -nosleep -video ddraw -skip_gameinfo -effect none -nowaitvsync -noreadconfig -mt ROMNAME

Listed 5 times, with 5 different ROMNAME's.  Then from a command prompt, just run the batch file, and check back when its done to get some numbers.  Here are my results from a little over a year ago - http://forum.arcadecontrols.com/index.php?topic=72776.msg826587#msg826587 (http://forum.arcadecontrols.com/index.php?topic=72776.msg826587#msg826587)

As to which build is better, beats me, but you can make several options and see for yourself!