Monday 18 July 2016

Cable Management: Improving Cooling in My Gaming PC, Part 2

So here was the situation: I had moved a couple of components around inside the computer to try and improve the flow of air coming into the case. Things had improved considerably, but 3DMark was still saying that at 92.6% framerate stability so there was still work to be done.

So many cables!

The most obvious thing to do was deal with the thick bundle of cables going through the middle of the case. I had used a cable tie to make it as narrow as possible but even at the thinnest part it had a diameter of about 2cm. I knew that at some point I wanted to tidy things up, and finding out that even with all the fans on the case I still wasn't getting enough cooling was motivation to put things right. There were two things in my way:
  1. The CPU power cable that comes out of my power supply was only just long enough to reach the socket on the motherboard. In my old PC the PSU had been mounted at the top of the case so the cable didn't need to be very long, but UNICORN-31 has the PSU at the bottom.
  2. I'm really bad with cable ties. I had a handful that came with the CPU cooler but had already wasted most of them trying to tie up cables and then realising I needed to move them!
Solving the first problem was pretty straight-forward: I just needed to buy an extension for the power cable, which I found on Newegg for about $3! Then I could run the cable through the cavity that the case creates behind the motherboard. I almost had a problem because the hole in the motherboard mounting plate was partially blocked by the motherboard itself, but with a bit of pushing I managed to get the surprisingly wide plug head through the gap and plugged in to the socket.

The obvious answer to the second problem is to just buy a whole bunch of cable ties, but I found something even better: reusable velcro ties! This was a huge help for me as it meant I was completely free to experiment with how I secured the cables and even tie things back temporarily whilst I worked with other cables. I really can't recommend them enough!

With this new-found confidence I tackled the bundle of cables. These could be broken up into a number of categories: main power cables for things like the motherboard itself and the video card, smaller auxiliary power cables for things like the hard drives and optical drive, fan control cables which run from the case fans and CPU cooler, and the myriad of tiny wires running from the control panel on the case that do things like make the power switch work or illuminate the hard-drive access LED. The goal of cable management is to have as much of the wires as possible sitting in the gap behind the motherboard, so step 1 was to untie the cables from each other and push them through the nearest hole.

It seemed like the obvious choice to tackle the bulky power cables first, especially the motherboard cable since it's probably thicker than all the other wires put together. I also have a lot of unnecessary wires of this type because the PSU is presumably designed to support a second graphics card, and also because my old case had a lot of LEDs which had their own dedicated power cable. As you can imagine, this proved to be the hardest part of the whole project. The gap for cables on this case isn't very wide, so anywhere were two of these thicker cables overlapped made it difficult to close the case. 

After about half an hour trying different ways of keeping the cables as separate as possible I decided to change tactics. Instead of running the excess of the main motherboard cable into the cavity, I used the small area in front of the power supply. I also ran the smaller power cables through this area and tucked them into the cap underneath the hard drive.

The last obstacle was the auxiliary power cables. The cables themselves are pretty thin but they have a number of fairly large plugs attached since they act kind of like wall outlets inside the computer (you can see one in the photo above, it has the white molex plugs attached). Again, my PSU has way more of these than I actually need as it has two such cables, each with four molex plugs. All the fan cases are connected to just one plug, and the optical drive needs a plug as well, which leaves two un-used on one chain and a whole other chain to spare! Eventually I found the perfect place: in the empty drive bay below the DVD drive, out of the way of the fans but still in a central position so that all the components that need them can be easily plugged in. After that it was easy to secure the smaller cables behind the motherboard and close the case!

Much better!

As you can see there are now no cables running through the main area of the case. You can see the larger cables tucked into the bottom, and some of the smaller cables through the larger hole in the motherboard plate. Not the tidiest case, perhaps, but much, much better than what I had before!

Now came the moment of truth: with the case still open I turned the power on to make sure everything was hooked up and working properly. At first everything seemed to be okay: the familiar beep from the system speaker and pattern of LEDs showed that the motherboard was happy. Then, I caught a whiff of something burning and panicked! Had I run a cable too close to something hot? Was something not seated properly? This could be really bad! No, as it turns out, my wife had chosen that exact moment to light a candle in the next room! After sharing a laugh and giving my heart enough time to climb back down out of my mouth, I checked everything out on the computer and found it to be working perfectly.

I had one more trick up my sleeve for improving the cooling, but wanted to see the results of my labour with the cables. Closing the case back up I ran another benchmark and was pleased to discover that 3DMark was now reporting a 99.6% frame rate stability (at some point I need to re-run this test because we had had the house's AC running for a while and the ambient temperature was much lower than when I had been experiencing problems). Not exactly a lot of room for improvement, but I had already spent the money on a fan card and wanted to see what difference it made.

I had never heard of adding extra fans to a computer before, let alone one that mounts into a PCI-slot and blows air upwards. It seems like most people use these to increase the flow of air into their GPU, but since my video card already has two pretty good fans I wanted to use this to improve cooling on the top of the card. I mounted it in the slot directly above the video card, close enough to suck the hot air away from the top of the card and blow it towards the output fans at the top of the case (as well as provide more air going into the CPU cooling tower. As you can see from the picture the card plugs into the standard molex power cables, which I had positioned in the nearby drive bay and thus reached easily.

Once again I ran the benchmark and was amazed to see the result now at 99.7%. My time working in my university physics labs tells me that this is probably not a statistically significant result, but pleasing nonetheless! I'm also very pleased that the fan card's LEDs are the same colour as the case fans.

So that's how I managed to sort out the cooling in my computer, only spending around $20 in total and just using a bit of common sense. Things have been working well on the computer since then, although I have yet to try out one of the games that was giving me the most trouble. I'll report back when I have more to talk about.

I hope this was informative and interesting for anyone else like me who's a novice with building computers and is a bit unsure how to proceed with cable management. It seems to make a much bigger difference than I expected, and is very much worth the time and effort.

Edit: I re-ran the stress test twice after a day of not having the AC on in the house, with an ambient temperature of 26°C and the results were 99.5% and 99.6%.

Friday 15 July 2016

Air Flow: Improving Cooling in My Gaming PC, Part 1

It's been a couple of months since I built my computer, and recently I decided that I wasn't quite finished with it yet. I had just finished playing Uncharted 4, not quite ready to jump into a big commitment like the new Witcher 3 DLC, and I wanted to test out what the new rig could do. As it so happened, one of my friends had gifted me the new Mad Max game on Steam, so I decided to see how well UNICORN-31 coped when confronted with a triple-A video game not yet a year old.

The answer, it turns out, was not well. The game would run fine for about 60 seconds and then start to get awful frame-rate drops that made the game feel like it was running in slow motion! I tried fiddling with the graphics settings for a while but even on the lowest this still happened. I read up about it online, found a number of people with similar problems who all recommended different things, none of which worked for me, and decided that this was why PC games tend to be cheaper than console ones: sometimes your specific hardware setup is going to clash with the way the game is made and not work perfectly.

I moved on to another game, Divinity: Original Sin, which I've owned for a while and wanted to try out, especially since they released a free 'enhanced edition' upgrade some time last year. Things initially seemed good, the gorgeous 3D title screen running at a smooth 60fps. But once again, when in-game, things began to chug after a couple of minutes. Divinity doesn't have nearly so many knobs and sliders in its graphics options, but after trying a couple of variations I was still getting the same problem. From what I read online, my conclusion was that I had a problem with cooling: when first starting a game when the graphics card and CPU were cool everything was running smoothly, but as soon as things began to heat up inside the case performance would drop significantly. The message was clear: I needed to improve cooling inside my computer! 

One of the things I've learned at my time at Facebook is that if you're going to undertake a project, it's important to be able to measure its success. So the first thing I did was take advantage of the Steam sale and buy 3DMark, an application used to benchmark the performance of gaming PCs. It offers a few different functions, including a benchmark suite which renders various graphically intense scenarios and measures how well the system handles them, and a stress test in which it plays the same loop over and over again to show if system performance degrades over time. The results were much worse than expected: the benchmark ran around 10fps, and the stress test showed a stability of only 12% in framerate! I opened up the case and assessed my options.

The first thing that occurred to me was the position of the hard drives. Hard drive bays are always located towards the front lower part of a computer case, which means that they tend to be right in front of the main input fans. When building the computer I put my solid-state drive (SSD) in a lower slot and the hard-disc drive (HDD) above it (see picture), because I knew that platter-based hard drives actually create heat whereas solid-state drives do not and thus it would make more sense for the HDD to be in a more direct air-flow. I also left a gap between them because it matched up with the spacing of the plugs on the power cable. As a result, the bulky hard-drive was blocking one of the fans providing air-flow into the case! A quick swap relegated it to the bottom of the case and put the much smaller solid-state drive in the slot directly above it, meaning that the two input fans were now much less obstructed.

The second thing I looked at was the positioning of the video card. I had it mounted in the top-most PCI-slot, which meant that there was about a 2cm clearance between the top of the card and the CPU cooling tower. The GPU has a pair of built-in fans on the underside which blow air upwards into the heat-sink, which cools the underside of the card nicely. My thought was that with the top of the card so close to the cooling tower and with relatively little air blowing across it this side of the card might be getting too hot. So, I moved the GPU to the bottom PCI-slot, so that the top of the card would get more air blowing over it.

After closing up the case and running the stress test again, I was pleased to find that the stability was now 92% (the benchmark was still pretty low, but it's designed for much higher-end GPUs). Whilst that's a huge improvement over what was happening before, it's still not a pass according to 3DMark. There was still work to be done!

I decided that now was the time to actually make the effort to sort out the huge bundle of cables going through the middle of my computer case. As you can see from the picture, they form a trunk about 3cm in diameter at the widest point which can't help the air flowing from the front of the case. It's a bit hard to see but I also have the power cable for the CPU running diagonally from the bottom centre (where it comes out of the power supply) to the top left (where it plugs into the motherboard) because that's the only way the cable would reach! As a result, it touches both the GPU and the cooling tower, which doesn't seem like a good idea!

Look out for Part 2 where I'll talk about what I did to tidy up my cables, as well as add a bit more control to the flow of air through the case!

Friday 8 July 2016

Jam Enslaver Plays...Shadow of the Colossus - Episodes 08, 09, 10 & 11

As expected, not a lot has changed in my recording setup for the last month, so I haven't had much to write about here! I'm planning on doing a bit more work on my PC very soon related to improving the cooling and finally sorting out the cables, but until then here are the latest four episodes.