How a larger girth helps avoiding fires – a cautionary tale about power cables

Here are three power cables. Do you see what’s different between them? Hint: One of them is a serious fire hazard.

I don’t know about you, but I have a box full of computer cables that I amassed over the years, and whenever I need a cable, I grab one from the box. There are plenty of power cables in that box, and I never thought twice about which one to use for a PC. Until one episode about two years back. The PC that I was using was a real high end killer machine – I don’t remember the exact specs, but I know that it was a $1000 Intel CPU, so I believe it was a Core i7 Extreme, paired with a high end Geforce card (I believe a GTX 660 or 680). I was playing a game, when suddenly I heard a popping noise and saw sparks falling to the ground. Like, literally sparks. At first I thought that the power supply blew up and tried a new one. After some more trial and error, we finally found out that is was the power cable that melted and sparked.

I had never seen that happen before. I knew that the super high end power supplies had a different connector (IEC 60320 C19 instead of C13) – but I didn’t think that there was any difference for regular power supplies.

Turns out that the thickness of the wires inside the cable matters a lot. This makes sense: Electricity going through a wire heats the wire up – the more power, the warmer it gets. If the wire isn’t thick enough, it will literally melt and can then cause a short, or like in my case, sparks (and potentially a fire). One of the standards used for wire thickness is called the American wire gauge, or AWG for short – you may have seen this used for speaker wire. A cable that you buy will have a number – like 18 AWG – which describes the thickness. Lower numbers are thicker, so a 14 AWG wire is thicker than an 18 AWG wire (do note that there is a difference between a wire and a cable – a cable is one or more wires plus insulation and connectors).

In the above picture, there are 14, 16 and 18 AWG cables with C13 connectors shown. Monitors tend to ship with 18 AWG cables, which is why I have a bunch of them. But 18 AWG power cables are not suitable for powerful PCs. They might be suitable for lower end PCs (that can safely run on a 450W or less power supply), but even a single 95W CPU and 8-Pin powered Graphics Card (like a GTX 1080) might draw too much power for the cable – a fire hazard waiting to happen. The cables will have their gauge written on them, or etched (which is harder to read).

Now, before you go and buy a bunch of 14 AWG power cables, do note that the thicker a wire is, the stiffer it is. 14 AWG cables are generally very stiff, so if the PC is close to a wall or the cable needs to make a bend for another reason, you might be putting a lot of force on the power supply connector. In general, 16 AWG should be perfectly fine to at least 850W – possibly more.

The strife for a great whitebox server case

Update 2017-07-25: I found a case, see at the bottom.

My home setup is a bit of a mess. That’s mainly because I haven’t properly planned out my needs, and now I have a Simple File Server that doesn’t accommodate my future growth, an old server to run VMs on, and some random assortment of hardware to do backups on.

So, I’m now making a list of my actual needs to build one new server to rule them all, sometime in 2018. The list of needs is fairly short:

  • Enough CPU Power to run about 6 VMs
  • Space for an ATX motherboard, to not limit options even if I end up with a Micro ATX board
  • ECC RAM
  • Enough disk space for my stuff
  • Redundancy/Fault Tolerance for my disks
  • Ability to do proper backups, both to an on-site and an off-site medium
  • Low Energy Use

Most of these requirements are fairly straight forward: For the CPU, a Xeon D-1541 (e.g., on a Supermicro X10SDV-TLN4F-O) or a Ryzen 7 PRO 1700 will do fine. For the hard drive, using my existing WD Red 3.5″ drives gives me the storage. After considering RAID-5, I’m gonna pick up a LSI Logic SAS 9211-8I controller to do RAID 1E instead, with RAID 10 being a future option.

The real question is though: Where to put all that stuff? That led me down to the rabbit hole of finding a server case. The needs seemed simple:

  • Space for at least 4x 3.5″ drives (ideally 8) and 2x 2.5″ drives (ideally 4)
  • Power Supply on top, so I don’t have to worry about overheating if putting the PC on the floor
  • Don’t look like crap. If possible, no Window, no lit fans, not designed like 1960’s Russian military hardware
  • Absolutely no tempered glass. If I can’t avoid a window, it needs to be plastic/plexiglass.
  • Want: Ability to hot swap at least some of the drives, so some backplane
  • Ideally $150 or less

Now, the “don’t look like crap” part is, of course, highly subjective. Still, I’d definitely prefer the look of a Corsair Carbide 100R over their Graphite 780T. The power supply positioning changed from the top to the bottom in recent years. This is because a modern CPU and GPU produce a lot of heat, so the old way of “have the PSU suck out the heat” no longer works well. Also, water cooling isn’t super-niche anymore, so radiator space is needed.

I’d like to hotswap drives, so one of my ideas was to look at some rackmountable case, but in that price range, there isn’t much. I found the Norco RPC-4308 which would be pretty awesome, if not for a small detail: The power connector on the SATA Backplane is a 4-Pin Molex connector. Now, while there is a problem with Molex to SATA Power Adapters catching fire, this is not a concern here as the power is properly routed through the backplane. No, my concern is that Molex Power is not SATA compliant. SATA Power is a 15-Pin connector:

Now, the fact that there are 3 pins each for 5V and 12V isn’t so much a problem (that’s more a side effect of how thin the pins are and concerns sending enough current over one of them). The problem is rather that some parts are completely missing. There’s no 3.3V power, no staggered spinup and no Power Disable with a Molex adapter. Arguably, 3.3V isn’t needed by most drives, and power disable is almost an anti-feature outside the data center. Still, the question is: Why invest into a system that isn’t fully compliant?

I haven’t seen any other rackmount cases with hotswap trays that fit the price range. There is a tower case – Silverstone CS380 – that looks awesome, but also suffers from the Molex power. Next up was looking at 5.25″ cages that hold up to five 3.5″ drives. There are some nicely priced and not too shabby looking ones out there (e.g., Rosewill’s RSV-SATA-Cage-34, but once again, buyer beware: Molex power, so that’s a no for me. I am currently looking at Silverstone’s FS303, FS304 or FS305. I’m not sure if putting five 3.5″ drives in three 5.25″ slot is a bit too closely packed, even with the low-power WD Red drives. But even ignoring the FS305, I could get six drives in four slots, or four drives in three slots, so that’s pretty good.

This now leads to the next problem: Cases with 5.25″ slots are becoming rarer and rarer. This makes sense, since many people don’t even have optical drives anymore, and those that do only need one bay. I need at least four, better five or six. So, how many PC Cases are there that…

  • Have four to six 5.25″ bays
  • Have the power supply on top
  • Don’t look like crap
  • Don’t cost more than about $150
  • Can fit an ATX mainboard

Spoiler warning: Almost none. I spent quite a bit of time looking through the offerings on Amazon and Newegg and on many manufacturers websites, and it seems that modern day gamer-cases and really cheap mini tower cases have completely replaced everything else on the market. Now, there are a few cases for Mini ITX boards that are interesting, like the Silverstone DS380, which seems like a popular NAS case these days. Still, my goal is to not compromise unless I really have to.

I’m still researching, but here’s my current shortlist:

  • Lian Li PC-8N – discontinued, but still available on Newegg for about $100. 4x 5.25″ bays, PSU on top
  • Antec NSK4100 – discontinued, but still available on Newegg for about $50. 3x 5.25″ bays, PSU on top
  • Corsair Carbide 200R – about $65, my choice for my own PC, 3x 5.25″ bay, PSU at bottom
  • Rosewill Legacy QT01 – about $100, 3x 5.25″ bay, bottom PSU
  • Fractal Design R5 – about $120, gorgeous case, but only 2x 5.25″ bays, so I’d have to seriously consider if I really want hotswap
  • Cooler Master N400 – about $60, only 2x 5.25″ bays and bottom PSU, but looks pretty nice, like a workstation
  • Cooler Master CMP350 – about $85, 4x 5.25″ bays, top mounted PSU, incl. 500W PSU, seems discontinued
  • APEVIA X-Cruiser3 – about $70, 5x 5.25″ bays(!), and the design should be good for some social media points
  • Buying something used – especially old tower servers or workstations. Don’t really want to do that, I’ve learned that name-brand complete systems usually mean some compromises in case design that I don’t like

If I go with a case that has the PSU at the bottom, I’d have to consider a PSU that has the fan in the back or can be mounted with the fan pointing into the case. There aren’t many PSUs with a fan in the back left, one option is the Antec EA-380D Green (which has 5x SATA connectors).

It definitely seems harder than it should be to build a whitebox server these days than it used to. Sure, the components are cheaper and more powerful than ever, but it seems that cases have stopped serving the market. I can see why people would rather buy a Synology NAS, or get some old rackmount server for cheap (Dell’s R720 should really come down in price now as thousands are being replaced), or don’t care about hotswapping, but still, it feels like the PC case market has regressed since the legendary Chieftec Dragon (which were also sold by Antec under the SX name) were every enthusiasts choice.

Maybe it’s indeed a sign of the times, where the real innovation happens in the Mini-ITX and gaming spaces, while everything else becomes a specialized device offered by someone.

Update 2017-07-25: I found a Thermaltake Urban S41, which hits most of the things I want. It looks nice and clean, it has 4x 5.25″ bays, 5x internal 3.5″ bays, and a even a temporary hotswap bay on top. There is plenty of cooling, with a 200m fan on top, 120mm fans in the front and back, and an optional 120mm fan at the bottom. The Power Supply is mounted at the bottom, but the case actually has feet that elevate it quite a bit above the floor. Of course, like all nice tower server cases, it is discontinued, but Amazon still had a few for $100.

I’ll add an ICY DOCK FatCage MB153SP-B, which houses 3x 3.5″ SATA drives in 2x 5.25″ slots. I might either add another one of those, but I’m also seriously considering 2.5″ Seagate BarraCuda drives. They go up to 5 TB on 2.5″ (at 15mm height), for a similar price as 3.5″ IronWolf/WD Red. I’m not sure if using a non-NAS drive is a good idea, but then, vibration/heat/power usage isn’t really a concern with these drives. In that case, I’d likely use an ICY Dock ToughArmor MB994SP-4S for 4x 2.5″ in 1x 5.25″, but it’ll be a while before I need to think about that. Who knows, maybe by then there will be 2.5″ Seagate IronWolf, or a 2.5″ WD Red bigger than 1 TB (I run two of their WD10JFCX in a RAID-1 currently).