Effects of a PSU upgrade

Posted on March 21, 2015 with tags tech.

First, GPU upgrade

Old videocard

My current video card was getting a bit long in the tooth. I kept delaying the upgrade, because newer Radeon cards are pretty inefficient, energy-wise, and I didn’t want to upgrade my PSU as well.

My old card had a TDP of 150W, and I was looking for upgrading to something in the same ballpark. While there were more current similar cards, the performance benefit was not that great - to get a real boost, I’d need to upgrade to something 200W+, if not 250W.

Additionally, I was focused on AMD-only cards because of Linux open-source support, even though newer AMD cards don’t support EXA anymore (plain 2D).

Surprised to learn about Nvidia Maxwell

While looking at what AMD cards to upgrade to, I happen to learn about the now ~1 year old Nvidia Maxwell architecture, which is - surprisingly - much more energy efficient. So efficient, that I could upgrade to a top-of-the-line card, with around 6× performance on most benchmarks compared to my current card, with only a 25W TDP increase.

I couldn’t believe I missed this for almost a year, just because I was focused only on AMD cards.

I research some more, I try to console myself about going back to Nvidia’s binary blobs until Nouveau supports GM20x card well, but in the end the results seem too good to ignore.

Upgrade: in-game performance and noise

For the card I bought, Nvidia says a PSU with 500W output is the minimum. That matched exactly the PSU I had, and it was a quality producer (Seasonic), so I bought the new videocard and installed it.

Performance was, surprisingly, as expected: my new card is faster at maximum settings than my old card was on low settings in two or three games that I tested. So all good from this side.

On Linux, moving to the non-free Nvidia driver was a walk in the part, thanks to the maintainers of all things Nvidia: thanks! Last I used an Nvidia card, many years ago, it was a bit more painful. And yes, Nvidia doesn’t enable all monitors upon boot, requiring some reshuffling of the outputs for multi-monitor work. Finding that I still had an .nvidia-settings-rc in my homedir from ages ago was fun :)

The downside was that the system was noisier under load; slightly noisier in some games, to much more noisier in others. This didn’t match my expectations, since the specific version of the card I bought was not overclocked and had extra large fans, and with only a +25W TDP it shouldn’t have been significantly noisier. Well, that’s it, I said, not all marketing/reviews should be believed.

One interesting thing was that I wasn’t clearly able to pin-point what was generating the additional noise.

PSU upgrade

I was thinking anyway about doing a PSU upgrade as well, since my current PSU was even older than my videocard, and was at the limit.

Dust…

So I bought a PSU as well, and spent about half a day installing it. Why half a day? Because the new PSU is modular, and the combination with the case I have means I could redo the cabling inside my case, significantly.

In the process, I found a lot of accumulated dust which I cleaned. I also found out that parts of the CPU cooler fins were blocked by dust, so the fan was not as effective as when new. I also realised that one case fan was no longer effective in its position, since I have no HDDs that need cooling (this case is split between MB and HDD/PSU areas), so I could move it in a place that cools better the various PCIe devices.

… and silence!

After all was said and done, the PC booted up just fine. Everything seemed correct, the new position of the fan was drawing in cold air and pushing it over the PCIe cards, so it was time to see if all the cleanup had any effect on the behaviour under load.

So I start a game, the card gets slightly noisier compared to idle, and stays there. I go on playing for 10 minutes, which would have been more than enough to heat the whole system enough that it becomes noisy, but nothing, just slightly above the normal “PC is on” noise. Before all the upgrades, my old card was definitely noisier when playing…

I don’t know if there is a single, key factor, or if it’s a combination of all of:

  • better CPU cooling
  • PSU with higher wattage, which means it has to work less for the same load; at idle these PSUs are very silent, but not so much at 80-90% of the maximum
  • better cooling of the video-card, since it doesn’t only recycle the air inside the case, but actually has cold air pushed over it.

In any case, I’m happy now. I got much better performance (5-6× is nothing to laugh at) for slight increase in energy consumption at load (~+25W). If I had stopped here, it would have been good enough. But spending 3 hours cleaning and simplifying the cabling means I also got a much quieter PC.

The only downside is Linux with binary drivers. Waiting now for Nouveau…