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Hello everyone,

Based on information in this thread ...
http://www.fractalforums.com/general-discussion/needs-faster-desktop-processor-for-deep-zooming-%28integer%29/
... and a benchmark test in this thread ...
http://www.fractalforums.com/movies-showcase-(rate-my-movie)/mandelbrot-set-1000-zooms-e301-21000
... I've began searching for information about what would be the most powerful computer currently possible to build for a reasonable price.

The processors that catched my interest were the amd opteron 6272. So far I've been thinking of a setup like this:


So far I've done a lot of research and I think this will probably work fine. Most important are of course the CPUs, because they do the rendering. The amd opteron 6272 are relatively new processors. They're the same bulldozer architecture as the fx-8150 that stardust4ever bought (see the first link above), so that means good integer performance. This was confirmed by information I found about this architecture. This image comes from wikipedia:



There's 2 integer cores for each float core. 2 Of those integer cores and one float core form a single module which some people consider 1 core, others don't. What it comes down to is that the integer performance is good. Basically, that's the architecture.

Compared to the fx-8150, the 16-core opteron 6272 is like 2 of those fx-8150 in one chip. Considering the benchmarks of the fx-8150 by stardust4ever (see the second link above), I think that even though the clock speed is lower, it is currently the best way to get a fast computer for fractal rendering. Alternatives would be intel (hella expensive) or fewer cores. More cores forms a problem because that would require a motherboard with 4 sockets (expensive), and that requires a professional operating system like windows server. I know windows 7 professional and better support 2 CPU chips and 256 cores. It also requires, of course, extra CPUs, which are expensive.

I kind of decided to draw a line there: €2000 for my setup should be possible and I don't want to spend much more than that. Consider €2000 is a lot for a computer, but the performance boost would be enormous and I think it would be well worth the money.

I am aware that the motherboard needs a different computer case because of the EATX formfactor.
I am aware that the motherboard has 4 channels for RAM, I'm considering using 4 GB strips to save money.
I am aware that double RAM is needed because of the 2 CPU sockets.
I am aware that the kgpe-d16 motherboard's bios doesn't always support the AMD opteron 6200 series processors. Information on this:
http://dlcdnet.asus.com/pub/ASUS/mb/SocketG34(1944)/KGPE-D16/Menual_QVL/KGPE-D16_Interlagos_Support_new.pdf
I am aware that the speed per core is low, but that's no problem because there's always enough to render.

Now there's one problem: does it actually work as well as I'm thinking? I've found a lot of information about it but I'm afraid I'm overlooking something. Does this work well on windows? On newegg.com people seem to be using these CPUs on windows and they're positive about them, on the other hand I'm reading everywhere about a bulldozer patch microsoft is developing for windows, to make use of the architecture more efficiently. Any ideas?

Product page with reviews on newegg.com:
http://www.newegg.com/Product/Product.aspx?Item=N82E16819113036

The Windows patch for "Bulldozer" functions by redistributing running tasks between the "Modules" of the processor (where one "Module" is a pair of integer cores plus one associated floating point unit).

The default behaviour of Windows is to fully load as few modules as possible. As an example, consider a Bulldozer with four cores, i.e. two modules. If you have two active tasks, Windows will put them both on a single module, and put the other module to sleep. This saves power, and allows the active module to boost its clock speed a little bit, using up some of the thermal headroom.

The patch reverses this behaviour. A patched Windows in the above example would put each of the two tasks on its own module. This would tend to consume a little bit more power, and would reduce the potential for dynamic clock boosting. But each task would now have roughly double the amount of some (not all!) execution resources at its disposal, so this is almost always a gain in computing throughput.

The default behaviour of Windows is more desirable for a laptops computer, where power is at a premium. The patched behaviour is probably more desirable for a desktop machine, where power and cooling are much less of a problem.


However, for a fractal production machine, the patch is unlikely to make a difference, because:

- either you are using some old single-threaded application, that will always run alone on its own module, with the other modules being turned off,

- or you are using a modern, fully threaded fractal generator, that will always fill up all cores on all modules (because fractal generation is typically a massively parallel workload).


The computer will simply not spend a significant amount of time in partially loaded state, so AMD's patch is neither needed nor can it make a difference.

Before i had no much problem with rendering the problems was do something else  while rendering (that as you know may take hours)
do  everything else was a pain, Firefox was  unresponsive,the file explorer took ages to change directory and even more to display images

Anyway mind that i mostly use Mandelbulb 3D that works  at 32 bit, so can't anyway use more then 3GB ram , but may become quicker if no other process compete

Some encryption algorithms might indeed be a good indicator for overall multi precision integer arithmetic performance. But I am unsure if AES is one of them. The picture is muddled further by the fact that the latest processor models from Intel and AMD have special hardware support for AES (in the form of a few dedicated instructions and execution units). So these benchmarks are now testing the special hardware and not the general execution resources of the machine.

First of all, I'd like to say something about the raw power of AMD Bulldozer when it comes to Fractal Extreme. People have been repeatedly stating again and again that the Sandy Bridge 2600 outperforms the AMD Bulldozer platform, but I believe that is a misnomer because most benchmarking software uses float calcs, not integer.

The Bulldozer platform gets less operations per clock per core than the Phenom II, but it makes up for this with more cores. I have also noted through experimentation (by using the "affinity" setting in Task Manager) that loading two integer threads on a single module, without varying the clock speed, takes about a 20% performance penalty compared to running the two threads on separate pipelines. As far as Windows 7 Task Manager is concerned, the threads are grouped this way, (0,4) (1,5) (2,6) (3,7) with (x,x) denoting a single pipeline (2 cores). I imagine floating point would incur a nearly 50% performance penalty, or something close to that.

As it turns out, assuming Dinkydau's i7 2600 processor is configured correctly, he's got 4 cores (and a total of 8 threads due to hyperthreading, which will only provide performance benefit if the other thread stalling the CPU, which isn't likely with Fractal Extreme) operating at 3.4Ghz

My FX-8150 was overclocked at 4.2Ghz. I did some testing at different clock cycles by adjusting the multiplier, and the change in render time was near exactly inversely proportional to the change in clock speed. Since everything (RAM, Northbridge, etc) else stayed exactly the same, the only bottleneck in this scenario was the raw clock cycles.

Dinkydau, I did some crunching on our render times to see what our render results would have looked like per core per Ghz (lower is better).

AMD FX-8150 @ 4.2Ghz (8 cores) = 2:48 (168 seconds)
AMD Phenom II 955 @ 3.2Ghz (4 cores) = 4:55 (255 seconds)
Intel Sandy Bridge i7 2600k (4 cores) = 7:35 (455 seconds)

Bulldozer single core @ 1Ghz = 168 x 8 x 4.2 = 5644.8
Phenom II (K10) single core @ 1Ghz = 255 x 4 x 3.2 = 3264
Sandy Bridge single core @ 1Ghz = 455 x 4 x 3.4 = 6188

Despite it's shortcomings, the 1Ghz bulldozer core actually beat the Sandy Bridge, but the older Phenom II wins hands down, so it may actually be in your best interest to get the last gen Opteron (if you can somehow equal the number of cores and clock cycles). By my calculations, if I take the 3264 figure for the Phenom II, and divide it by 6 cores and again by 3.2Ghz, then I would presumably get a render time of 170 seconds for a Phenom X6 1090T processor running at stock clock speed. That's nearly the same performance value as my overclocked FX-8150!

3264 / 6 cores / 3.2Ghz = 170 seconds

Or, if I simply set the multiplier to 18 and run the X6 at 3.6Ghz, essentially forcing all cores to run simultaneously in turbo mode (at rated turbo speed they should all be able to run completely stable), which is possible and safe to do with a good aftermarket heatsink, then my theoretical render time should be:

3264 / 6 / 3.6 = 151 seconds, which would actually outperform the 8 Bulldozer cores!

The reason why I bring this up, about the older Phenom II outperforming the bulldozer, is that you may be still be able to purchase the last generation AMD Opteron and get similar performance value out of it. Sadly, it appears based on the out-of-stock status on the NewEgg website, that the Phenom X6-1090T desktop processor is no longer being manufactured anymore, but people were recommending that over the Bulldozer, and there may be some truth to those statements.

I could be mistaken, but if the (45nm, K10) six-core Phenom II X6 1090T can outperform the (32nm, Bulldozer) 8-core Bulldozer FX-8150 on the desktop platform, then there is a good possibility that the (45nm, K10) Magny-Cours 12-core may be able to outperform the (32nm, Bulldozer) 16-core Interlagos at similar clock speeds. And that is for Integer performance. Floating point will definitely get an even higher yield on the older architecture, since the newer Bulldozer processors cut the actual FPU count in half.

A couple of more thoughts on this...

If you can wait a few months, the second generation of AMD Bulldozer processors are right around the corner, codenamed "PileDriver". I don't know about the server market, but here's a quote from Wikipedia regarding the Desktop processors. I may or may not decide to upgrade my existing setup to PileDriver at a later date, but it's supposed to solve the issues regarding lower throughput per clock per core.

Also, if you are going to be spending all this money on a new workstation PC, you might as well get a good EATX case as well. I recommend:
http://www.yycase.com/yy-w2xx.htm#

It's heavy as hell, but it's worth the money, plus it dampens the internal sound/vibrations much better than a lightweight aluminum case. I got the yy-w201 with option B (hard drive bay with 92mm intake fan and mounts for up to 5 HDs). You'll likely never use up all of the expansion bays. Two of mine I replaced with drawers where I keep loose screws, driver CDs, and small parts.

Another thing to consider, is it really worth the amount of money required to build a high-performance server platform which will likely be bested by desktops in a couple of years? The reason why I am asking you this, is that I spent a large sum of money ($5000 USD) to build a similar system back in 2005. In fact, I am still using the case, power supply, and DVD-Drive of that original system. At the time of build, I actually had to wait a couple of months after building before I could really start using it until Microsoft Windows XP x64 was released. Originally, I had Red-Hat Linux running, which I didn't like too much and wasn't compatible with Windows software. The system had two 2.4Ghz Opteron processors (single core) and 4 Gigs of RAM. Had I waited just a year or two more, I could have gotten a cheap dual-core Athlon 64 desktop processor which would have danced circles around the old Opteron setup. Another issue at the time was lack of support for 64-bit Windows XP drivers for most of my hardware. I had a silent PC with no audio because the motherboard manufacturer (Tyan) hadn't even released 64-bit XP drivers for the integrated sound. I'm not sure if they ever did or not. And most software that existed at the time I built the PC didn't support multithreading, so the single-threaded performance gain I got out of the behemoth was only slightly better than my old Athlon XP rig.

Of course, a lot has changed in the past 6-7 years. 64-bit software drivers are everywhere now, and many software apps are available which support multiple threads/CPUs. A couple of neat little quirks about server processors: You can run like 20 instances of a program which is a known resource hog, and the server processor won't choke on it like a desktop will. And I say this meaning my original system had only two physical single-core CPUs, so it supported 2 execution threads, but I could load my computer down with 12 separate instances of Bryce 5 (a 3D ray-tracing software I liked to use back then, which unfortunately did not support multithreading until version 6 came out a couple years later) and still be able to play my favorite N64 games in a full-screen emulator without dropping much fps. My Athlon PC could barely handle the emulator running in a window with nothing else running in the background, though the video card may have been a factor in that. Basically, server CPUs can handle a lot more thread thrashing before they start to choke than a desktop CPU can (they're basically designed from the ground up to be overloaded), but single-threaded performance of anything (like games) will be abysmal. That's why desktop processors have fewer cores but much higher clocks.

Anyway, just think carefully before you buy, and I hope you get excellent results with whatever you decide to purchase. LOL, long post...

EDIT: If anyone is interested, I have uploaded a copy of my benchmark *.fx file, you can find it here and compare your computer's performance:
http://www.fractalforums.com/fractal-exteme/fractal-extreme-performance-benchmark/

Sorry, but some of the info presented here is inaccurate. Back in the olden days when CPUs had only one core, and computers had very little RAM, your statements about uninstalling unneeded software may have been accurate. And some of what you are saying definitely holds true if you have some sort of malware that is wasting CPU or network resources. But as long as your harddrive has a reasonable amount of free space (15% or more) and has been defragmented withing the last month, and you have 2Gb or more of RAM, and a multicore CPU, these things shouldn't be an issue. To test whether or not some rouge application is wasting CPU resources, open the task manager and select the processes tab. Click the CPU load button at the top to arrange the list of programs by their CPU load. Most idle processes will show little to zero CPU load when they're not doing anything. If not, you can terminate the process, or better yet, find out what software it's associated with and disable it. I use my large desktop machine to web surf and perform other tasks all the time, and it rarely if ever affects the render progress. If your render application is bogging down your web surfing or other activities, you can change the render application's priority to "low" and that should free up CPU cycles for other programs like web browsers. Don't ever change your render program higher than "normal" or your PC may become unresponsive. But it is in most cases unnecessary to uninstall things like LAN adapters and stuff. Windows 7 does needs to be set not to sleep if you plan on doing render jobs while you are away from the computer, and Automatic updates should use the option "download updates, but let me decide when to install them" otherwise the computer will automatically restart after it applies the updates and you will lose your work.

But on a modern computer with modern operating system, your CPU usage will be practically zero or at most 1% at idle, and about 50%-75% of your RAM should be freely available. A quad-core processor will typically do a render job twice as fast than a dual core at the same clock speed, so faster clocks and more cores typically mean shorter render times. Also newer processors often have updated instruction sets and more efficient pipe-lines, larger caches, etc, so your argument of salvaging an old computer from the scrap bin and then expecting major performance gains simply by modifying or removing unneeded software, without opening up the case and replacing a lot of hardware, is pretty naive. However, if you just want a box to surf the web on, an old dinosaur will probably do fine. You may get between a 2-5% gain in performance by tinkering with software/ cleaning up the hard drive, as opposed to a 100%-200% or higher gain by simply purchasing and installing a new CPU or CPU/Motherboard combo.

Graphics Cards (aka "Stream" processors) are only good for a limited number of uses. Generally, they primarily rely of floating point operations. Yes, a high-end Graphics card may have up to 3600 SIMD "stream" processor cores, but those are not equivalent to a true SISD x86-64 core. You would need to execute a separate instruction for each data point, which is not possible on a Stream processor. Say you need to multiply a thousand different data points by 3.141592, or change the alpha value on a thousand different pixels. With a SIMD, that is easy to do. However, coding fractal programs to utilize this architecture is not a trivial task. The output of each iteration provides the input for the next iteration, so you are not multiplying a thousand different data points by one single data point, but instead multiplying a thousand different data points by a thousand different data points. What's more, any kind of deep zooming requires arbitrary precision, meaning you are basically doing long-hand multiplication on a long string of integer values and adding them back together in a complex matrix. Even though it may be technically possible to do that on a video card, it would be difficult to code. Another issue here is that Video cards use floating point calculations, whereas arbitrary precision requires integer calculations. Doing arbitrary precision with floating point numbers is very messy and can lead to rounding errors which will ruin the integrity of the calculations.

Yes, GPU's are indeed a near-perfect math for 2D and 3D fractals, and several people on this forum use GPU techniques (also using shaders such as GLSL and HLSL). Each pixel can be calculated independently using the same code, and there is no need for synchronized memory access.

Also notice, that a GPU is not one big stream/vector processor, but is organized in smaller units (multiprocessors), which must apply the instructions to 32 threads in parallel (at least in Nvidia's architecture).

There are also higher-precision (more than 64bit) floating point libraries out there (at least for CUDA).

But keep in mind that it is much easier to find fractal software for CPU - I'm not aware of any deep-zoom implementation for GPU.

I'm asking myself the same question every few months.

I'm still using my good 5 years old computer with a Q6600 (5yo too). I upgraded the ram to the maximum supported (8GB) and buy a new gfx card from time to time (i have a very good GTX 470). The only reason i'll change the system is that i want more ram (i do more than fractal) and the motherboard don't support more than 8GB.

Being a sysadmin i'm able to play with much more powerfull computer (24cores, 64GB ram, stuff like that) and i'm not really impressed by their power (for fractal) compared to GPU, that's why i suggested learning GPGPU.

I pre-ordered my next computer, a Raspberry PI (ARM 700Mhz, 256MB RAM, some OpenGL capabilities. it's same CPU/GPU than an Iphone) : $35 ! 

I can't really point you to a configuration right now (i'm currently not following the latest PC Hardware market).
But my suggestion is still roughly the same. If you want a "good" computer :
- $2000 is a right price
- Intel CPU
- NVidia GFX card
- as much ram as possible.
- http://ark.intel.com/ is your best friend. Use it, always ! If you don't understand everything in the specification datasheet : learn !
- Be very carefull with the NVidia naming scheme, it always change from generation to generation (stupid marketing for gamers).

For the CPU, i'd suggest one of thoses 2 : http://ark.intel.com/compare/52213,63697
i7-2600 or i7-3930K, with a preference for the 3930K but it's more expensive (it worth it, imho).

The i7-3930K have more core and more Cache, lack an integrated GPU (you probably don't care) and have the same "turbo" speed, support more ram, with more bus and higher bandwidth.
For raw power, it's the best choice. (For gaming and general purpose, however, i'd suggest the i7-2600 unless money isn't an issue at all)

Or the i7-3960X of course, but it's much more expensive for little benefit, and can't fit with a $2000 configuration (you'll have to sacrifice everything else and you'll end up with a very very poorly balanced computer... don't do that!).

The gamer's choice for the gfx card on $2000 computers seems to be the NVidia GTX 580 (and dual 580 for more expensive computer). I don't know the 5xx generation so i can't say.
16GB RAM seems to be the standard.