44 Mac Pros Racked Up to Replace Each Rack of 64 Mac Minis

We were delighted at a seeing 96 MacBook Pros in a rack a couple of days ago which served as testing hardware. It’s pretty cool so see a similar exquisitely executed hack that is actually in use as a production server.  imgix is a startup that provides image resizing for major web platforms. This means they need some real image processing horsepower and recently finalized a design that installs 44 Mac Pro computers in each rack. This hardware was chosen because it’s more than capable of doing the heavy lifting when it comes to image processing. And it turns out to be a much better use of rack space than the 64 Mac Minis it replaces.

Racking Mac Pro for Production


Each of the 11 R2 panels like the one shown here holds 4 Mac Pro. Cooling was the first order of business, so each panel has a grate on the right side of it for cold-air intake. This is a sealed duct through which one side of each Pro is mounted. That allows the built-in exhaust fan of the computers to cool themselves, pulling in cold air and exhausting out the opposite side.

Port access to each is provided on the front of the panel as well. Connectors are mounted on the right side of the front plate which is out of frame in this image. Power and Ethernet run out the back of the rack.

The only downside of this method is that if one computer dies you need to pull the entire rack to replace it. This represents 9% of the total rack and so imgix designed the 44-node system to deal with that kind of processing loss without taking the entire rack down for service.

Why This Bests the Mac Mini

3 racks - Linux. Mac Min, Mac Pro
3 racks – Linux. Mac Min, Mac Pro

Here you can see the three different racks that the company is using. On the left is common server equipment running Linux. In the middle is the R1 design which uses 64 Mac Minis for graphic-intensive tasks. To the right is the new R2 rack which replace the R1 design.

Obviously each Mac Pro is more powerful than a Mac Mini, but I reached out to imgix to ask about what prompt them to move away from the R1 design that hosts eight rack panes each with eight Mac Minis. [Simon Kuhn], the Director of Production, makes the point that the original rack design is a good one, but in the end there’s just too little computing power in the space of one rack to make sense.

Although physically there is room for at least twice as many Mac Mini units — by mounting them two-deep in each space — this would have caused several problems. First up is heat. Keeping the second position of computers within safe operating temperatures would have been challenging, if not impossible. The second is automated power control. The R1 racks used two sets of 48 controllable outlets to power computers and cooling fans. This is important as the outlets allow them to power cycle mis-behaving units remotely. And finally, more units means more Ethernet connections to deal with.

We having a great time looking that custom server rack setups. If you have one of your own, or a favorite which someone else built, please let us know!

[Thanks to drw72 for mentioning R2 in a comment]

The Giant Flip-Dot Display at CES

Flip-dot displays are grand, especially this one which boasts 74,088 pixels! I once heard the hardware compared to e-ink. That’s actually a pretty good description since both use a pixel that is white on one side and black on the other, depend on a coil to change state, and only use electricity when flipping those bits.

What’s remarkable about this is the size of the installation. It occupied a huge curving wall on the ooVoo booth at 2015 CES. We wanted to hear more about the hardware so we reached out to them they didn’t disappoint. The ooVoo crew made time for a conference call which included [Pat Murray] who coordinated the build effort. That’s right, they built this thing — we had assumed it was a rental. [Matt Farrell] recounts that during conception, the team had asked themselves how an HD video chat for mobile company can show off display technology when juxtaposed with cutting edge 4k and 8k displays? We think the flip-dot was a perfect tack — I know I spent more time looking at this than at televisions.

Join us after the break for the skinny on how it was built, including pictures of the back side of the installation and video clips that you have to hear to believe.

Continue reading “The Giant Flip-Dot Display at CES”

LED clock lights up a dead Mac Mini

[Professor Shadoko’s] Mac Mini died. But since the case designs on Apple products are half the reason to buy them, he decided to reuse the enclosure by turning it into this clock (translated).

As with the binary clock we saw yesterday, this one uses a bunch of LEDs to display the time, but it does it in a way that’s a bit more readable if you know what you’re looking for. The face has been divided up into two columns. On the left is hours, then minutes and seconds in increments of five. To the right is AM/PM, with minutes and seconds in increments of one. If we’re doing this right, the time seen above is 10:23:42 PM on April 28th, 2012. The white LEDs below the date act as a digital pendulum, scrolling left and right as the seconds tick by.

The display uses two MAX7219 LED drivers to control the grid which is build on a big hunk of protoboard. An Arduino ties the whole system together with a Chonodot for accurate time keeping. There’s even an ambient light sensor which adjusts the LED intensity to make this readable in direct sun, or the dark of night. See a demo clip embedded after the break.

Continue reading “LED clock lights up a dead Mac Mini”

Speedier hard disk option for your Mac Mini

[Andrew] was left wanting by the slow hard drive in his 2011 Mac Mini. He set out to add a 10,000 RPM drive and we think he did a great job of pulling it off. Luckily he also took the time to document the process so you can try it yourself.

As with a lot of Apple products, a big part of this hack is just getting the darn thing apart without breaking something. Once that’s done, you’re got to do a little bit of interface hacking. To save space Apple uses a non-standard SATA breakout cable so [Andrew] starts by ordering a second hard drive cable from the company. He then soldered a thin wire connecting 12V from the motherboard to the 12V pin on a SATA connector. From there it’s just a matter of altering the original hard drive sled to make room for the 500 GB WD Velociraptor drive. It fits below the original and serves as additional space instead of as a replacement.

How-to: Windows Media Center on a Leopard network

We’ve been using Microsoft’s Media Center for a few years now and have grown to like it a lot. We’ve also noticed that more and more Apple computers have shown up on our home network and decided it was time to get everything working together smoothly. Follow along as we walk you through the hoops we jumped through to get everything cooperating. Continue reading “How-to: Windows Media Center on a Leopard network”