Well, I have to give it to you. If you're willing to code support for ztex on a Hackintosh, you are a better man than I am. I also run VMware. I notice the workstation version runs much better with win7 as a host than Ubuntu. Believe it or not, I ran a Win2k8 server as a VM inside Win7 (don't ask me why) running a web/SQL server. No issues for 5 straight months.
Regardless, good luck with your endeavor. I see you have a nice setup with the 1.15d although I have to say I like how compact the 1.15x is (big where it counts=heatsink
)
Cheers
The board is very much a Test Unit as per the child-like writing on the piece of MDF
I like the additional length and 'wind tunnel' feature of the 1.15d / Exp. Board 1.3 combo - and not just because I can bolt in a big SDHC card to run rainbow table apps etc. Purely focusing on BTC mining right now, I've run into big thermal problems with a 9 GHash GPU-based frame rig contraption (pics on the other thread here, won't clutter this one up). Running high-density units (in my first case, GPUs) horizontally, with the fan having to blow air *down* onto a heatsink, with maybe another hot unit sitting above or to the side, is just thermodynamically inefficient. The fans are working against physics, and if there's another GPU directly above the fan, then it can only blow red-hot air from the back of the upper GPU core onto the heatsink. Cue high temperatures and fans running at 85-100% capacity.
I've had loads of fan failures on GPUs and eventually switched to a vertical layout, where the main GPU exhaust points straight upwards. This allows convection to provide cool air for the fans to blow sideways onto the heatsinks... but with a high-density setup, radiated heat from the backside of the GPU next door is *still* a problem. The retail GPUs don't cool the rear side of their circuit boards and I've measured them at up to 90˚C in places using an IR thermometer.
With the 1.15x all-in-one solutions, the design is very much like a traditional GPU / CPU. A fan blows air down onto a big heatsink. Of course, the TPC is so much lower that my considerations are almost moot... but with the comment that the FPGA must have hit 90˚C (by Stefan, discussing when the active fan failed), there's room for making use of convective cooling as well as relying on downward-blowing physics-fighting fans
OK, so I'm a mad fan of the Apple G4 Cube. If there was a hope in hell of compiling Stefan's SDK for PowerPC then I'd be using my example (pride of place on my desk, kept alive at all costs, though not doing much right now after having burnt out 4 GPUs, 3 hard drives and a PSU) to control the FPGA array I'll eventually build.
Using the same concepts, look at the 1.15d and how it connects to the Exp Board 1.3. My picture above is my Test Unit as explained. My quad-board rig design (had to downsize from 5-board because the fans pushed the power budget too close to the PSU max output!!!! heh) will have each unit mounted vertically, with the power and USB connections at the bottom, in a Cube-styled enclosure with adequate venting for cool air to enter from below, rise up through the boards, and exit at the top.
I don't plan to use ANY active fans on the 25mm heatsinks supplied with the 1.15d boards. The cheap crappy fan on my picture above is there for safety, and I'll be removing it during testing to see whether the horizontal fan keeps the board cool enough.
You see, there's a tunnel between the FPGA board and the Experimental Board. Even with convection only, cool air will flow through this 'tunnel' and provide cooling to the immediate *reverse* of the FPGA, which will be getting hot. The Experimental Board itself will provide a heat barrier to prevent the back of the FPGA heating the front of the board next to it (remember it's high-density, like the GPU solutions).
I think this 'tunnel' and the ability to direct cooling air to the *back* of the board, something most people ignore with GPUs (and is a very significant heat load in high density rigs) is a great feature of the 1.15d setup, which is why I'll be going to use these rather than the optimised 1.15x boards.
Without tall, small-diameter fans on each FPGA heatsink, my enclosures can be made more elegant whilst still maintaining high density. I don't know what Stefan's 1.15x active cooling product is like, as I can't use it, but my experience with small-diameter cooling fans as per those used on older GPUs etc. is that they can make a horrible high-pitched whining noise. I'm sure Stefan's is a quality item but in 6 months, will it be making a racket like some of my GPU fans?
This is all moot if my design doesn't work, of course. I'm doing a Cube but having two 80mm PC case fans blowing cool air up from the bottom, and two identical fans at the top of the enclosure blowing hot air out. Inside a sealed acrylic enclosure, this should provide enough pressure to ensure air is *forced* through the 'tunnels' and through the pins on the FPGA heatsinks. We're only talking about 10W per board max, after all...
If there's a way to read the temperature of the FPGA core and feed this back to the fans, then a *really* neat automatic solution could be built - but to begin with I'll simply chuck a potentiometer in with the fans. I'm hoping that four 80mm 3W fans is massive overkill for my design, and the fans can be run slowly and *quietly*.
Put it this way, my girlfriend has put up with my GPU frame rigs for months now. The noise made by all the fans is enough to affect *my* sleep and I'm accepting it, not getting irritated by it. Hopefully my FPGA rigs, when complete, will be damn-near silent. It would be poetic to have the G4 Cube managing the FPGAs... but the Cube doesn't even have USB2 and I still haven't managed to compile the SDK on a reasonably-standard Intel Snow Leopard Mac yet... so my old first-gen AppleTV, which (with a bit of hacking) can be made to run the regular OS, may be put into use if there are no OS snags. Otherwise it's a Mac Mini.
Regardless, it's going to look cool, hopefully run cool, and whilst replacing 9 GH/sec is beyond my financial means at the moment, once I've got this SDK built on the Mac, I'll be discussing volume discounts and best deals with Stefan
