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Racking Mac Pros

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Re: Racking Mac Pros

#31
Wow, learn something new everyday. I thought everyone who did image processing and cared about performance used NVidia cards for the CUDA libraries. I never knew apple [GPU image libraries](https://developer.apple.com/library/mac/documentation/Graphi...) made AMD a competitive choice.

It is much more expensive, though a lot less engineering work, than buying some used Tesla's on ebay: http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m5...

or even brand new

Re: Racking Mac Pros

#33
post #19

Earlier quoted context omitted.

The Mac Pro isn't a great value in the datacenter space. It's a single socket server that's limited to 64 GB of RAM. It's not unusual anymore to throw GPUs in rack mount systems; most of them already have the PCIe bandwidth necessary to support 4 big GPUs so it's often just a matter of getting the right riser cards. Compare a Mac Pro to an HP DL360 that can hold 4 8-core Xeons (32 cores total) and over 200GB of RAM a…

Well, they're fitting 4 sockets and 8 GPUS in the space that's normally used by 4 sockets only. Also, if you're trying to sync raw images between OS X clients and the cloud, then you're going to need OS X servers in the cloud. It'll greatly complicate the clients workflow if they can't use their built in raw converters.

Right; which is why I was surprised that OS X stacks up as favorably as it does. But I wouldn't call it a great value since it's still much more expensive than a traditional rack mount setup. From a density perspective it's really not bad at all, which is a testament to how well-engineered the Mac Pro is.

Re: Racking Mac Pros

#34

Seems like you could have gotten higher density going vertical instead of horizontal. It would have been 50% taller (6U instead of 4U) but it could have held 100% more Mac Pros. A Mac Pro is 9.9 inches tall and 6.6 inches in diameter. 9.9 / 1.75 = 5.65 and 6.6 / 1.75 = 3.77 https://www.apple.com/mac-pro/specs/

This was one of our initial ideas for the design, but it boiled down to an airflow concern. There are some products that do this, such as http://www.h-sq.com/products/mprack/index.html

If you look at how the airflow works on that shelf, I think you'll see why I don't have confidence in that solution. The air paths to each system seem to be based on wishful thinking.

We also didn't need to go that dense after considering each host's power draw at full load. I design towards a 208v/3ph/50a circuit on each rack, and 44 Mac Pros at full load (plus a switch) are about 13.5kW in my testing. So we would need to build for 60A circuits, or not completely fill the rack, to make the vertical orientation worthwhile.

Re: Racking Mac Pros

#35
post #5

This is interesting -- they actually manage to get greater density out of this setup than many traditional rack mount systems offer. And to those questioning "Why would you use such expensive systems when commodity hardware is just as fast at half the price?" I would reply that the Mac Pro isn't all that expensive compared to most rack mount servers. If you're talking about a difference of $2000 per server, even acro…

Unfortunate for many who wish otherwise, it's very clearly a market they do not remotely care about.

Re: Racking Mac Pros

#36
post #19

Three possible reasons I can think of for doing this over using PCs or Linux servers: 1. Using the same operating system as the developers of the software, plus access to Apple's fantastic imaging libraries. 2. The Mac Pro, whilst expensive, is good value for money. The dual graphics cards inside it are not cheap at all. As servers with GPUs are fairly niche, this might actually be a cheaper solution. 3. The form fac…

The Mac Pro isn't a great value in the datacenter space. It's a single socket server that's limited to 64 GB of RAM. It's not unusual anymore to throw GPUs in rack mount systems; most of them already have the PCIe bandwidth necessary to support 4 big GPUs so it's often just a matter of getting the right riser cards. Compare a Mac Pro to an HP DL360 that can hold 4 8-core Xeons (32 cores total) and over 200GB of RAM a…

No sane person is putting GTX cards into a configuration with that level of power density, you'd have reliability issues from day one. This use case is exactly why Nvidia makes Tesla cards.

Re: Racking Mac Pros

#39

Seems like you could have gotten higher density going vertical instead of horizontal. It would have been 50% taller (6U instead of 4U) but it could have held 100% more Mac Pros. A Mac Pro is 9.9 inches tall and 6.6 inches in diameter. 9.9 / 1.75 = 5.65 and 6.6 / 1.75 = 3.77 https://www.apple.com/mac-pro/specs/

I suspect that the sideways orientation is motivated by cooling. The mac pro sucks air in the bottom and shoots it out the top, so if you stack them, the top machine is sucking in the bottom machine's hot air. In this orientation, the whole rack is sucking air in from one exposed side and pushing it out the other exposed side; much easier to engineer around.

Re: Racking Mac Pros

#40
post #29

It's really kind of mind-boggling that Apple makes and sells the Pro, which can be upgraded to a really nice high performance GPU workstation, but then doesn't sell the same hardware in rack mountable forms for clusterable computing. I'm sure they've performed some kind of market analysis for this, but there's enough differences between OSX and Linux solutions that for people who use HPC solutions (a growing market)…

Apple used to sell the rack mounted X-Serve, but discontinued that a few years go.
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