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[Thief^]

Keep in mind that an AMD 3Ghz processor is slower than an Intel 3Ghz processor, and that a very old 3Ghz processor is slower than the latest 3Ghz processor. 

Actually the AMD and Intel chips are pretty close these days, but AMD just don't make chips that match Intel's very fastest ones. So if you want truly insane performance (by which I mean about 10% more for 10x the price) you buy Intel's top-of-the-range. Anything below that AMD is normally cheaper for the same performance.

Especially with Intel's new chips' ability to run with either one core clocked very high or all cores clocked a little lower, which is very nice for single-threaded things like DF.

[jfs]

Say you have one dwarf hauling rock away from your mines. He has a one-tile wide corridor to run in, and he's completely alone. Even if you make the corridor four tiles wide, he won't move your rock any faster.
However, if you tried using four dwarves to move the rock through a one-tile corridor, it wouldn't four times faster, because they'd jam and have to lie down and stuff all the time. But four dwarves hauling through a four tile wide corridor, that'd be optimal.

[riffraffselbow]

It's 3.4 GHz per core.

I am not condescending, I just haven't been able to get a clear answer anywhere else...Are you absolutely positive this is true?

Indeed, this surprises me as well. I don't know otherwise, though, and I can verify that the rest of that post is accurate.

It's a bit confusing, because a GHz is not like a megabyte - it's a measure of speed not processing power. But each core is clocked at 3.4 GHz, so you have a "total" of 13.6 GHz of "speed." In other words, DF will run just as fast on a single 3.4 GHz machine as it will on a quad 3.4 GHz; because it uses just one core.

This is the theory. However, in practice, there is a finite amount of overhead in multi-threading. Now, this overhead can be very small, or it can be VERY, VERY large. It also depends on whether the actual code is multi-threaded at all; try running something processor intensive but completely unthreaded, and you'll see one core get pounded while the others twiddle their thumbs. Assume you'll get 1.25 cores worth of performance out of the average game on a dual core, and 1.5 cores of performance on a quad.

[Maggarg - Eater of chicke]

I assume it will run faster than on a single core anyway due to everything else going through all the other cores.

[Baughn]

I'd never be satisfied with less than 3-3.5x performance from a quad.

But the sad fact is, most game programmers are totally incapable when it comes to threading. The tradeoffs are totally different; all those nifty low-level optimizations and cross-class chatter get horribly in the way when threading.

It's fair to say that a program properly built for multiple cores will probably only be slightly faster on two cores as a single-threaded one is on one, since you have to use a much cleaner style. That pays off once you get to four cores and above, though, since it'll scale much better.

[riffraffselbow]

I assume it will run faster than on a single core anyway due to everything else going through all the other cores.

That's not the case. Apart from the rendering, NOTHING CAN "Go through other cores". Toady hasn't implemented threaded design in DF, it doesn't run multi-threaded. Your operating system and other things running on your computer can be offloaded to another core, leaving a core entirely to the whims of DF. But it won't run multi-threaded.

[random51]

I assume it will run faster than on a single core anyway due to everything else going through all the other cores.

That's not the case. Apart from the rendering, NOTHING CAN "Go through other cores". Toady hasn't implemented threaded design in DF, it doesn't run multi-threaded. Your operating system and other things running on your computer can be offloaded to another core, leaving a core entirely to the whims of DF. But it won't run multi-threaded.

I think you missed his point.  By everything else he probably meant Operating System, browser, quickfort, dwarf therapist, utorrent, winamp, dwarf companion, excel, vlc, etc.

Bind DF to its own core while everything else on the system runs on the other cores.

Back to the original post, quad core processors seldom match the individual core speed of their dual core brethren, which makes them less suited for the avid gamer. Somebody looking for the best performance should be looking for the fastest dual core they can afford.

I tried to explain this to gamers jumping on the Q6600 bandwagon, people who were selectively applying the "bigger is always better" mentality to number of cores instead of core clockspeed. They didn't listen. Meanwhile the smart ones bought faster dual core processors for less money, and are still happy with performance while the Q6600 people are already upgrading.

[KaelGotDwarves]

I assume it will run faster than on a single core anyway due to everything else going through all the other cores.

That's not the case. Apart from the rendering, NOTHING CAN "Go through other cores". Toady hasn't implemented threaded design in DF, it doesn't run multi-threaded. Your operating system and other things running on your computer can be offloaded to another core, leaving a core entirely to the whims of DF. But it won't run multi-threaded.

He's talking about the OS and other background services being done by other cores. In that case DF does benefit a bit from having at least a dualcore.

Yeah, with my overclock'd desktop, 4.6 ghz i7 920 version of this:
It was underclocked to 4.0 stable when I took this screenshot.
I can achieve this without an fps cap at embark- unpaused as you can see. Paused it rockets higher.


Course it's absolutely unplayable at that speed, and the fps rubberbands within a couple hundred frames per second. With migrants and digging out the map (the dwarf/item pathfinding is the single biggest drain on DF fps besides liquid flows and caveins), the speed will drop. But I can maintain a large map and 200 dwarves at playable 100ish fps (as long as I cage/cull my animals), which was impossible with my other computers.

The only games I've seen that really benefit from quadcore are valve games which have been optimized for multithreading, anything with lots of AI work like ArmA2, AI War: fleet command, cortex command's physics, games that are horribly optimized for PC and require brute force (GTA4)

As for AMD vs Intel - I don't know if I want to get into this here. hahahaha

I have plenty of both. I suggest you shop around and look for the best in your price range and go with that. There's no point in fanboying over tech because it always changes. On this desktop I went with an i7 920 because of the power to money ratio when overclocked cannot be beat, to the point that the new generation i7s and i5s have been gimped by intel simply because there's no reason to buy the $500+ chips when you can get a $200 chip more powerful than the $1000 EXTREME editions.

Assholes.

Phenom IIs can get you exceptional bang for the buck at cheaper prices, but the i5 isn't bad either. It's just not the old i7.

Intel... WHY WOULD YOU PUT THE DIE THERE AND INTEGRATE THE GODDAMN THING RARGHOASDGNLAESRH GIMP THE OVERCLOCK.

Such a step backwards. They're looking to make their integrated graphics systems destroy nvidia and AMD-ATI while controlling how the consumer uses their product. Price fixing through engineering design :/

[Jong]

I've got a i7 920 too but my fort is so monstrous that my FPS has been knocked down to 30.

Its something to do with having 150 z-levels and 10000s of blocks and stuff all over the place.

[Jurph]

Oh, it's only the rendering that uses a second thread, but that still means you get ~10% usage from a second core, in addition to the first one.

Baughn, I don't think it gets said often enough: your contributions on the DF rendering thread, especially making the first steps towards MTing DF, make a huge impact on DF.  Thanks again!! 

At the risk of starting a flame war, I'm looking forward to the day that Toady implements temperature, weather, and/or flows in their own thread.

[teloft]

Oh, it's only the rendering that uses a second thread, but that still means you get ~10% usage from a second core, in addition to the first one.

Baughn, I don't think it gets said often enough: your contributions on the DF rendering thread, especially making the first steps towards MTing DF, make a huge impact on DF.  Thanks again!! 

At the risk of starting a flame war, I'm looking forward to the day that Toady implements temperature, weather, and/or flows in their own thread.

Is there a plan to make it multi-threaded in future?

[Baughn]

Not really. Doing so would be a staggeringly immense undertaking, and there is a lot of low-hanging fruit that would speed things up more anyway, like implementing better algorithms for handling large number of rocks.

[gamegreen33]

I guess my question is, does anyone know from experience how well the processor I was looking at getting runs a 200-dwarf fortress, frame rate wise?

[KaelGotDwarves]

You mentioned 3.4 ghz, but what kind of processor?

AMD athlon? Phenom? Phenom II? Intel core2duo? Pentium? i3/5/7?

EDIT: Nevermind I missed the part down the page where you mentioned Phenom II.

It should run 200 dwarves at a playable framerate as long as you don't go crazy with animals or liquids. I suspect somewhere in the 30-50 range highly depending, of course, on embark locations and amount of items. Mature forts are always much slower. In the beginning you'll have no trouble maxing at something high like 200 fps cap. Note I do not own a phenom II, but have worked with them (one of the dozen (seriously) computers in my house has a phenom. They're a fine choice for great performance for the $$$- especially if you buy from newegg.

[bombcar]

Note I do not own a phenom II, but have worked with them. They're a fine choice for great performance for the $$$- especially if you buy from Newegg.

Are you saying they're Phenomenal?

/glasses
//yehaaw