Does compiling for various processors really make a performance difference?

[retrometro]

I naturally believe that a faster process makes for faster mame games (at least the more recent ones).  But given the same processor/system, has anyone done any testing to see if specifying the processor type makes a measurable difference?

My cab has an old Pentium 4 2.4GHz and when I compile for the hi score patch, i've tried specifying the processor and without and can't tell the difference.

Maybe it makes a bigger difference in substantially faster or slower cpu's?

[brian_hoffman]

Yes it does... Maybe 5% but it still helps..

64bit does wonders tho... But you need a 64bit cpu and OS to take advantage

[9innail]

When I compile for my specific processors I can get as much as a 10-15% speed increase.

[Lilwolf]

btw, anyone know what cpu I should compile for AMD 64 bit (32bit os) opteron?  (the extra cache workspace versions)?

[retrometro]

Yes it does... Maybe 5% but it still helps..

64bit does wonders tho... But you need a 64bit cpu and OS to take advantage

Do you know if anyone's done a matrix measuring fps for various processors and mame compiling options? 

How much of a gain do you get compiling for 64bit?  do you have to run your OS at 64bit also?

[TheShanMan]

You can only run 64 bit apps on a 64 bit OS, and there has been a fair amount of discussion of the speed benefits of 64 bit already, so have a look.

Probably no matrix exists, and IMO no need really. If you are experiencing performance issues with any games, then try compiling your own version with whatever options apply and see if it helps (it's so easy to do). Use the fps display for a before and after comparison. But if you're not experiencing performance issues and don't otherwise want to compile your own, then don't even worry about it.

People have told you their experiences with compiler options; now it's your turn to measure the difference.

[retrometro]

Probably no matrix exists, and IMO no need really. If you are experiencing performance issues with any games, then try compiling your own version with whatever options apply and see if it helps (it's so easy to do). Use the fps display for a before and after comparison. But if you're not experiencing performance issues and don't otherwise want to compile your own, then don't even worry about it.

Thanks TheShanMan.  I should add that one of the reason to ask for a matrix is to gauge how much money will make the best bang for the buck in terms of replacing my current setup.  The only thing I've found in terms of benchmarks are the the better the process the better the fps...   Plus a lot of the comparisons are with video and audio turned off to focus on the processor's performance.  Finally, they don't list old processors like my Pentium 4 2.4GHz.

What I want to do is see where my setup stands and see how much a cheap new or old system will bring it up to speed...   especially for some of the benchmark games like cruisin' usa, gauntlet legends, or star blade.  I don't care to buy the most expensive CPU/mb for my cab.

Finally, soft15KHz works great and I want to make sure if I find a bare bones system, the gfx card in the new one will be supported by it.  I know there's a compat gfx chart out there already beginning with her wiki on it.

thanks everyone.

[retrometro]

looks like compiling mame specifically for my P4 2.4 makes a 5-10% diff in some games.  maybe when i tested before, the games were maxed out.

[TheShanMan]

Ah, that's an interesting reason for wanting that info. I can tell you that I built my system in January and didn't exactly go top of the line. I spent around $200 for case, mb, processor, memory, and video card (I think that's all I bought - rest of the stuff I had on hand). It plays all non-chd games I've ever tried without a hiccup, and several chd games as well. I don't care about many chd games, though I did try California Speed and noticed some hiccups. I don't have a steering wheel yet, so I didn't care about trying to optimize for that game or figure out if it was something I could solve. Probably if and when I get to the point of caring about that or other problematic games, I'll make the switch to 64 bit.

So as always it obviously depends on what you want to play, but probably for the vast majority of people you don't have to have some top end gaming system to get perfect performance for your games.

Hope that's helpful. Good luck choosing your hardware!

P.S. I went with an AMD processor. I'm not as up on processors as I used to be, but it used to be that AMD gave better bang for the buck, so I used that logic in my choice and I'm totally happy with it.

[Jdurg]

Yeah, for a good while the AMD line of processors was the best you could get for your money, but that era ended when the Core2Duo CPUs from Intel hit the market.  When that happened, AMD got hit hard as those Intel CPUs now offer the greatest "bang for your buck".  AMD now only has the lead on the very low end processor market which anyone building a cab for MAME should avoid if they want to run anything.

Basically, the gist of compiling in 64 bit and specifically for a processor is if the standard build of MAME gets you to about 95-96% of full speed with your current setup.  In that situation, compiling specifically for your processor class can give you the final % points needed to be runnign smoothly and flawlessly.  If you are struggling to run a certain game, don't be fooled into thinking that a custom compiled 64-bit build will suddenly make it playable.

[massive88]

Yes it does... Maybe 5% but it still helps..

64bit does wonders tho... But you need a 64bit cpu and OS to take advantage

Do you know if anyone's done a matrix measuring fps for various processors and mame compiling options? 

How much of a gain do you get compiling for 64bit?  do you have to run your OS at 64bit also?

Heres a link to the tests I did when I built my newer mame computer - http://forum.arcadecontrols.com/index.php?topic=72776.msg826587#msg826587

Its a small sample size, but I saw a 5%-20% increase in performance depending on games using the 64bit binary and OS.

It depends on the specific driver how much of an increase you will get, but if you want to push your performance, going 64bit is definitely the way to go.  You always have the option of running the 32-bit binary on some of the games if you need to (like gradius 4).

[retrometro]

Thanks to everyone for their input.

BTW brian_hoffman, what cpu were you running your benchmarks on?