Um...hi?
It's been a seriously long time since I last posted anything and to be honest I wanted to just crack on, get this thing done and then update you after the fact. But it's never that easy and as per usual, great progress got halted and then life and health gets in the way.
I was all ready to get the metalwork FINALLY painted, assemble this and finalise my tube runs (the first attempts were pretty much bang on!) when I hit a few snags and ended up missing the excellent weather. In retrospect that's turned out to be a small blessing as planning out and prepping the custom PSU cables has opened a massive can of worms. Let's revisit some of the early design choices to get a bit of context for this post. Go grab a drink and settle in
As you may recall, the internal redesign of the case sees a 360mm radiator filling the entire bottom chamber with the PSU repositioned to the front. This post is where I introduce the body work and detail the plans and history if you want more detail.
The idea for this PSU placement is to have the fan draw air from the main body cavity, hence the grid pattern, and exhaust it into the wee gap between the PSU body and the tempered glass side panel. From there, the intention is for that exhaust air to rise through convection into a space that exists between the body inner and the outer aluminium skin, possibly with a small fan gently wafting to assist (In Win's form over function design and resulting wasted space has proven to be a real boon
). After that the air can do whatever it wants; we're not talking about a sealed box here, so there's plenty of gaps and places it can flow and escape, and possibly even using the outer skin as a heat soak and then just radiating away.Now, all those years ago the intention was to reuse my Silverstone 450W SFX power supply. Their modular cables have a 1:1 pinout, so there's none of this 18+10 pin with a truck load of doubled sense wires. The only slight issues was this 1:1 pinout does cause a 180 degree twist, however my PSU orientation combined with the 24 pin placement on the Maximus VIII Impact actually negates this twist, allowing me to interleave the wires instead of crossing over. The end result is a nice and reasonably-flat set of cables I can neatly tuck away and hide since I wanted to be as cable-free (visually) as possible in the first instance.
Some time later I changed my mind when I decided that I was going to overclock the 6700K. The original Asteria was a i5 2500 non-K and a mild overclock on the Titan, so everything ran fan on the 450W Gold PSU. Clocking the bojangles off the CPU and GPU with an aging 450W PSU that doesn't get super fresh air likely wasn't going to cut it, hence the upgrade to the Corsair SF600 Platinum.
I didn't realise this change of PSU was going to cause so many headaches until now.
So, the actual problem
This is the stock Type 4 24 pin cable laid out with the connectors oriented as required.
It naturally falls quite flat and is fairly tidy, despite having the 18+10 pin and sense wire doubles going on; the top 10 wires kinda flow across the top third, the bottom 17 wires (yes, only 17 wires in an 18 pin connector) kinda flow across the bottom third, with only 1 sense wire being idiotic.
The problem is, when you actually plug the cables into the PSU the 10 and 18 pin connectors have to cross over!
So now at some point along the length you have this big mass of wires bunching up. Doesn't look so bad with the stock cable, but when making up the custom set it gets properly ugly and unwieldy, exacerbated by changing how I want to present cables.
There's only 32mm from the top of the modular connectors to the glass side panel, and the originally-planned cover plate takes up 1.5mm of that. Even with some serious bending and stuffing, 30mm isn't enough space to handle that crossover bunch and then flatten out to exit that chamber. And aesthetically, the "hidden cable" idea fails when the cover plate is mounted so far away from the case body. But since I now want to show the cables after introducing a little blue into the monochrome colour palette, there's nowhere to tidily place the crossover anywhere along the mere 250mm length this ATX cable will run.
So, I flipped the PSU over and with it all my cable woes go away.
Not only do you now get a lovely flat run of cables (including the 8 pin EPS) that can gently arc out of the PSU and S-bend through the case into the motherboard, but the GPU cables now also flow directly out (left side PSU placement out of the left of the chamber) and the DDC pump can plug directly into the PSU on the bottom-right. Hell, even the internal mains extension cable (which I realise I've never actually shown you) has an extra 6cm or so slack on it, whereas it was ever so slightly too short before.
Sounds great then, so what's the problem? The PSU no longer has direct access to air.
Remember this bad boy?
The Asus Fan Extension card works perfectly in that 20mm cavity, but now blocks half of the fan. The grid cutouts in the case (that bit is still stock) cover up half of what's left.
Such a shame, because the runner mount works so nicely too allowing easy removal through the rear side of the case.
And even if smothering the PSU wasn't the issue, the only real place it could draw air from is that upper case gap I mentioned earlier planned as a convection dump. Cycling hot air around in this little restricted hot box is not a good idea.
Solutions? Or just moaning?
So, after yet another mighty tale of woe in this build log, what's the take home? Do I somehow cram the cables into that limited space and cover them up as per the original plan, or do I devise some insane method to magically feed the PSU fresh air just to have pretty cables?
Rhetorical question is rhetorical
OK, let's mark up yet more portions of the stock case to chop up (there's very little left now outside of the outer skin) to free that PSU's fan. And let's also chop out a chunk of that lower lip too, and make a corresponding hole in the main body underneath.
Let's also redesign the Fan extension card's runner mount so it sits flush with the outer skin of the case, rather than the inner body. That opens up the 20mm cavity for some air circulation...
...and it still slides in and out to mount the card and all the fans.
Once the cutting is done later on, we'll have an open channel from the main chamber up through the bodywork and into that 20mm cavity.
It's time for a centrifugal fan and air duct.
This is only a proof of concept (and the fan is upside down purely for display purposes here) with a 50mm 5V fan.
At full speed it's not all that noisy and blows a good volume of air through that little chimney. Enough, in fact, to give my hand a chill as I was feeling around to gauge the exit pattern and air volume. I don't want the fan on all the time though as the PSU has a zero fan mode. I have a few different centrifugal fans for 1U server racks to play with for this with the intention of controlling their speed based on a temperature probe next to the exhaust of the PSU; if the PSU's fan isn't spinning then the air duct fan doesn't spin, once the fan does spin up I'll switch the fan duct on to feed air into the PSU.
I have a nice 3 pin 12V fan already and I'm waiting on a PWM version too. I also have a couple of different air duct designs in the works too. One is just a bigger version of that proof of concept with some better airflow direction, the other will look to have a 2nd output to aid exhaust convection (but that involves ripping the fan out of its existing housing so I'm waiting until I have some spares).
Hopefully I'll have the result of this sorted soon so I can share, rather than leave you hanging for another 9 months
Given this damn project has entered it's 6th year, I'm eternally grateful to anybody reading this who actually still gives a damn! But for anybody who's knew to this
Catch you soon!
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