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[Darekun]

I understand that in addition to needing a fast CPU, DF also performs massive numbers of memory accesses, so while saying "it runs off ram" is not quite precise, having a fast-access RAM may be important to performance.  You likely don't need more than 2gigs at this time, but the access speed and cache of that ram will be important.

Yep — it runs off RAM, but speed-wise, not size-wise. CPU speed matters less, ever since the Pentium 4 era at least, than RAM speeds and FSB speed.

(Amusingly, had GPU problems a while ago, spent some time on motherboard graphics while picking a new one. DF didn't care :J)

Unless you have other CPU-intensive things going on, no need for >2 cores running. Shutting down half of a quad-core can get you room to overclock, but if you're building a computer for DF, better to have that dual-core speed out of the box.

[etgfrog]

optimaly for costs vs power....as high dual core processor(2nd core devoted entirely to df as it isn't multi threaded) as posible although wont go any higher because companies have stoped increasing the frequency and just focused on adding more cpus, a high frequency ram would help quite a bit too but that isn't that major.

[Tellemurius]

1gb+ DDR3 1066Mhz+ Ram
any 2.0Ghz+ processor with a L3 cache should be fine

Dwarf Fortress runs on pure ram and just uses the hard drive to save the game so SSD won't make much of a impact other than loading and saving.

FYI this is entirely incorrect. Dwarf fortress uses the processor for almost everything. Ram is used in worldgen but otherwise has little impact on in-game FPS. If you don't believe me, just open up your task manager and have a peek at where the strain is: you'll find it is almost entirely CPU. Similarly, making DF large address aware helps a lot with worldgen, but you'll find it makes little difference to the game itself.

really? i wouldn't know that considering my brother's computer always blue screen and was slow as shit even with his pentium 4, then i found out it ate all of his 512mb 

i already stated the minimum system requirements on the processor and fast ram and alot of ram helps when you got big worlds and doing some number crunches. I52500k is the best processor for this, can overclock it for faster speeds and really shouldn't need to spend more. As for AMD...... well Phoenoms are good enough and unfortunately the bulldozers didn't prove much so don't expect to pay more than $125 on them and get something better.

[runlvlzero]

Don't go single core even with DF. You'll want another core to do other stuff, like run your OS and utilities, and the graphical rendering which Baughn put in its own thread for us.

So I should not be using the set affinity command to run the game on a single core now?

[alexandertnt]

Don't go single core even with DF. You'll want another core to do other stuff, like run your OS and utilities, and the graphical rendering which Baughn put in its own thread for us.

So I should not be using the set affinity command to run the game on a single core now?

If you do set the affinity to a single core, the threads that run for the SDL portion of the game will run on the same core as the game. Its best to let the OS manage it, as they tend to be pretty good at this.

[NW_Kohaku]

1gb+ DDR3 1066Mhz+ Ram
any 2.0Ghz+ processor with a L3 cache should be fine

Dwarf Fortress runs on pure ram and just uses the hard drive to save the game so SSD won't make much of a impact other than loading and saving.

FYI this is entirely incorrect. Dwarf fortress uses the processor for almost everything. Ram is used in worldgen but otherwise has little impact on in-game FPS. If you don't believe me, just open up your task manager and have a peek at where the strain is: you'll find it is almost entirely CPU. Similarly, making DF large address aware helps a lot with worldgen, but you'll find it makes little difference to the game itself.

Tellemurius is right, it's all about RAM speed.

It might look like it's dragging on your CPU, but it's really all just huge amounts of memory that the game is loading constantly. 

Pathfinding, temperature checks, objects in the game just being there in memory, these things are what really slow your game down, and they do so because it's massive amounts of data that can only be stored in RAM that need to be constantly checked, and where the accessing they do is often (at least in the case of Pathfinding) so random as to be extremely difficult for the CPU to make accurate guesses as to what RAM to load ahead of time, causing the CPU to constantly have to abort its slicing, leading to large amounts of burnt cycles spent processing bad data (and giving false positives on CPU usage). 

What you need is the fastest RAM latency possible.  Pretty much all the other specs are not going to be a bottleneck in any reasonably modern computer you can buy.  Just focus on RAM latency.

[runlvlzero]

@Alexandertnt

Awesome, this is great news! I'm one of those barely knows enough about computers people who aggressively over power use everything lol.

On a side note, I never had a machine as snappy as one I built in like 2003, with an AMD FX, damn that CPU was insanely snappy, snappier it seems then the quad core I have now. which runs 2.80 Ghz.... I spent nothing on the CPU it self... I can't believe I sold it for 1000$ (mainboard and two nice GPU's in SLI mode) back in the day... I did some googeling, the FX series has held its price point too damn well, its scary... If you want to build a rig just for older games designed around single threading stuff its something to look into.

http://www.cpu-world.com/CPUs/K8/TYPE-Athlon%2064%20FX.html

[Tellemurius]

@Alexandertnt

Awesome, this is great news! I'm one of those barely knows enough about computers people who aggressively over power use everything lol.

On a side note, I never had a machine as snappy as one I built in like 2003, with an AMD FX, damn that CPU was insanely snappy, snappier it seems then the quad core I have now. which runs 2.80 Ghz.... I spent nothing on the CPU it self... I can't believe I sold it for 1000$ (mainboard and two nice GPU's in SLI mode) back in the day... I did some googeling, the FX series has held its price point too damn well, its scary... If you want to build a rig just for older games designed around single threading stuff its something to look into.

http://www.cpu-world.com/CPUs/K8/TYPE-Athlon%2064%20FX.html

Or just get any Intel Sandy Bridge CPUs that blew everything out of the water for single-thread apps. Hell the cheap ones sadly do a better job than any of the new AMDs (i had hopes for bulldozer damnit)

[runlvlzero]

It is insanely creepy how tiny the die has gotten.... I just looked up the sandy bridge, apparently 6 years is a long time in computing history now-a-days. 90nm to 22nm.... hello quantum mechanics... lol

[Tellemurius]

It is insanely creepy how tiny the die has gotten.... I just looked up the sandy bridge, apparently 6 years is a long time in computing history now-a-days. 90nm to 22nm.... hello quantum mechanics... lol

and its gonna get smaller, say hello to 14mm in 2014.

[Beyondrepair]

To summarize:

- Memory size ceases to matter once you got an amount that lets DF fit in comfortably together with the OS and whatever applications you are running.
- Memory access speed is incredibly important. That said, if you got 512 MB of really fast memory it would be too little and amazingly slow nonetheless simply because the OS would resort to hard drive swapping.
- Get a dual core at least, no reason to have a single core because you will still be running other stuff than DF in the background.
- Overclocking your CPU will help to some degree (because operations will execute faster on data already loaded into the CPU cache memory) but the final bottleneck in main memory speed will remain.

[Thief^]

How do I tell my computer to run everything else on another core?

In task manager, on Processes tab, you right click individual processes and select "set affinity...". You set DF's affinity to one core and all the other processes to the other.

You really don't need to, Windows is perfectly capable of balancing the hundred-odd processes you're probably running. You can't even alter the affinity of some processes. And lets not forget that DF actually uses at least 2 threads, so constraining DF to one CPU core is actually slightly counter-productive.
You're better off:
1: setting the priority of DF to High
2: Killing anything else that's using more than a few percent of CPU time

[Shinziril]

There are generally two numbers given for memory, speed and latency.  Speed is given as a frequency, generally in megahertz (MHz).  This is the number of "clock cycles" per second the memory can handle.  The higher the frequency, the more data can be pumped in and out of the RAM in an optimal situation (i.e. all data is lined up and ready to go, or similar).  Due to fancy technological tricks, the various DDR memory standards (the most recent version is DDR3) can actually transfer data twice per clock cycle, so the actual "core" frequency will be half that listed ("1066 MHz" DDR3 will have a 533 MHz core clock, "1600 MHz" DDR3 will be 800 MHz, etc).  This is important for the second number, latency.  Latency is typically given as how many memory clock cycles of the memory it takes to access a random bit of memory within the module.  This is important for DF, since the lower it is, the less time it will take to get the information about a random piece of rock or whatever.  To get the total time latency, you divide the number of clock cycles by the clock frequency.  As an example, DDR3-1600 RAM with a latency of 8 cycles will take 8/(800 x 10^6) = 10 nanoseconds to find a random requested segment of data.  DDR3-1066 RAM with a latency of 6 cycles will take 11.25 nanoseconds.  Note that the second example actually has slightly higher latency despite the lower clock-cycle count, since its clock cycles are slower. 

High speed, low latency memory generally either uses a slightly higher voltage than normal (which may or may not wear our the memory faster/be slightly unstable, depending on the quality of the chips), is somewhat more expensive than normal memory (since they have to screen the memory chips to find the ones that run fast and reliably at normal voltages), or both.  At the moment, I believe even good quality memory is still quite cheap, certainly much less than, say, a high-end graphics card. 

[mogthew]

Fast CPU, ram matters but not nearly as much.

Tests have shown ~5% difference when switching from single channel to dual channel - http://www.tomshardware.com/reviews/PARALLEL-PROCESSING,1705-15.html

[Shinziril]

That testing was more about whether more bandwidth (how much data it can pipe at once) would improve application performance.  More RAM channels won't improve latency for a random memory fetch, they just make it transfer faster once it finds it.  Dwarf Fortress is a very unusual program with its own requirements.  I will agree that it is likely not bandwidth limited, but I suspect it could easily be affected by memory latency.