The first flush
With fancy computer equipment comes annoying computer maintenance. Today has been a challenge! Thankfully finished, mostly. It’s been roughly six months since I took the plunge and built my own custom watercooling loop for my computer. Since today is the first flush, I figure I can tell the story and talk about how it went. Spoiler, it went both better and worse than I expected.
My desktop computer has been a labor of love. I mean apparently all my electronics are a labor of love, but my computer was a choice and one I don’t exactly regret, even though I hate myself some days for building it. A lot of the things we do in neuroengineering requires data processing and the fastest way to get data processed is to use a fast computer. When I built it, it was as good as I could afford and I saved forever to buy the parts. However, I didn’t have the time, money, or frankly the skill (IMO), to custom watercool the computer, so I opted for a sealed all in one (AIO) watercooler. It did its job and the CPU, an AMD threadripper can really put out some heat, so I stand by the watercooled choice.
Things were going well… then it clogged.
All of the AIO watercoolers say that you do not need to do any sort of maintenance, and this is true, it’s a sealed system. However, they do fail because things corrode, metals react to the heat/liquid, or there’s always the chance something is growing inside (seriously). Turns out the first watercooler I bought had a lot of issues with clogs. So almost a year later when mine failed, I chalked it up to that, bought a new one from a different brand that had good reviews and happily lived with my computer for another year, until the problems came back.
The computer would lag, studder, and just generally act like I was running some serious software, but I would literally just be writing something in word when this was happening. A quick check at the CPU temps confirmed I had a serious issue and once again I was left with either replacing it and rolling the dice once again, or making something myself. This time, I opted for the later because you can only spend so much money every year on an AIO watercooler until it would just be cheaper to build and maintain your own custom loop.
For those interested I detailed everything I did start to finish here. That also contains some of my earlier efforts and other technology fails I’ve had. Anyway point being I build a whole super cool custom loop and it’s been a dream ever since. A few weeks ago I got a reminder from my task management app tick-tick (I wrote about here) letting me know it was time to flush the loop. Since this is a custom watercooled solution, I need to change the coolant (like you would on a car for example) every six months or so. Some people opt for a whole year, after seeing what it looked like, nope, not happening.
You’ll have to forgive me because I was in such a hurry to get everything done I didn’t really take photos. However, I did want to accomplish a few things, the first was to reseat the waterblock for the CPU. Everything has ran just fine, but my main concern was that I could do better and since the computer was apart it wasn’t too much more work to do.
Basically I wanted to pull off the waterblock (seen below between the ram… the red things), clean off the thermal paste, clean the block if needed (it needed), and reapply thermal paste then reseat the waterblock. My big concern was that I over applied thermal paste OR the block wasn’t seated properly. I just had a feeling since the temps did weird things, nothing ran super high, but I had a feeling it wasn’t as good as it could be.
I also wanted to recut and rebend one of the tubes. I have extra and one of them worked, but it didn’t fit as snuggly as I wanted, so since the computer was in parts, I took care of that as well. Lastly, the temperature sensor from the waterpump was plugged into w_in on the motherboard. This is the “water pump inlet” temperature sensor and it’s where I assumed I should plug in the temperature sensor from all the documentation. It turned out I could only view that temperature in the bios, so it did me absolutely no good. Since I have a handful of other places to plug it in that I can read in windows, I made the switch and now I should be able to see what the coolant temperature looks like.
This will be handy to keep track of ambient temp, coolant temp, and CPU temp so that I know how well the system is performing. Prior to this I only had CPU temp and ambient temp to compare, so adding coolant temp will tell me how fast heat is being dissipated. Since I have 720mm total radiator size, I should have more than enough to keep the coolant temperature from building too high (e.g., more heat is being produced than can be removed by the radiators).
So everything got addressed, it took a lot longer than I had planned, but I did find some things that makes me glad I did the flush now. I managed to bend the tube replacement in one shot, so that was nice and it fits a lot better than the previous one did. There was some sediment in the coolant or at least it looked like there was. That can build up and gunk up parts, specifically the microfins on the waterblocks for the CPU and GPU. There did look to be some sort of growth on some of the o-rings, probably algae, but the coolant should have additives to prevent that. I did take apart the waterblock for the CPU and give it a thorough cleaning because there was some sediment inside from what it looked like, not a lot, but enough that I figured it was worth the extra time since I already had it apart.
The flushing part was a bit of a mess. I managed to spill, because of course I did. I also realized my drain plug location wasn’t ideal, but after some serious thought about bending new tubes to accommodate it elsewhere, I realized it was basically the only place it could go and that’s better than not having it. Below you can (poorly) see the drain line (soft tube coming toward the camera) connected to the drain plug.
Water is heavy, so it wants to sit at the lowest point of the loop and the drain plug is at basically the highest point. The lowest point is the smaller of the two radiators and I thought about moving it (I actually tried), but I don’t have the right fittings for it, it would look messy, and I would need to bend another very complicated tube.
Overall though I think it went well. I’m currently just letting it do its thing circulating the coolant and getting the air out of the system. Since there was probably some left over distilled water (I flushed twice with distilled water to clear the loop), the process wasn’t as complicated as it was when I first put the loop together. The liquid foamed quite a bit due to all the air (old photo from the first fill shown, again poorly, below)
While it was a pain to do all this, I still prefer it over the cost of replacing the AIO every year. After two years the loop will have paid for itself and then some, so I’m okay with needing to do the flush every six months or so if it means the computer is going to continue to work reliably.