Big Adam
19-08-2002, 10:38
Okay, since I posted the description of my SV24 mod (see below) a few days ago, I've had a couple of PMs asking for details/hints and tips.
I don't mind the PMs, although discussion should be conducted on the forum, but the content of the questions set an alarm bell ringing and as moderator I reckon I should lead by example.
Please, everyone who is contemplating a PSU mod, be aware that this is the one area of your PC that really should NOT be tampered with and any mods made to it should be made with extreme care.
I cannot stress enough that although I have cut away at the PSU casing in my SV24, the 80mm fan effectively shields all parts of the PSU internals that the discarded casing used to. The rest of my PSU casing remains intact and I do NOT advocate the full removal of the PSU casing.
Without getting into a big debate as to whether it is the current or the voltage which can do you harm, the fact remains that the PSU is plugged directly into the mains supply. Mess with this and make a mistake and you run the risk of a serious accident.
My apologies to anyone who finds the above deeply patronising, but to the people who have contacted me and told me they have removed their PSU casing PLEASE PLEASE BEAR THIS WARNING IN MIND.
The PSU fan is a problem, it's noisy and I didn't have much faith in either swapping it for a quieter 40mm fan or 7V-ing it. It shifts sod-all air in stock setup anyway. I was also unhappy with the way the PSU did not vent out of the case (as in later Shuttles) but simply recirculated the air within the unit. As you know, the SV24 relies on one 60mm fan and a few vents for it's entire air throughput.
Through a bit of fiddling I found that if I cut away at the PSU casing where the 40mm fan sat, I could sit an 80mm fan between the PSU and the case (a little bit of careful cable routing was required. The right hand side of the fan sat flush with the front of the case and the left edge sat perfectly level on the retainer clip of the first RAM clip.
With a fan blowing INTO the case, half the air blows across the PSU, providing cooling (don't rely on passive PSU cooling) and half the air blows across the case in the direction of the CPU. By using a low volume Papst fan (12dba) I achieved sufficient cooling for my C3 900Mhz even with a 7V-ed 60mm low volume Panaflo providing the exhaust. Heatsinking for the CPU comes from a chunky unbranded heatsink that I found for £2 on eBay. It fits in nicely with the low-profile PCI card I have at the moment but would be too tall for a full height card. If I ever install a more powerful CPU, I'd swap out the HSF for a Thermaltake Golden Orb.
As a bonus, the small bracket which normally retains the PSU, holds the 80mm fan in place perfectly. This combined with the fact that the fan fits perfectly flush with the edge of the chassis means that one 80mm hole, an aluminium mesh filter and some blowhole trim give a really nice 'stealth' finish with no need for extra external fan screws/fingerguards.
All the above combined with small rounded cables mean that I run at around 30C at idle rising to around 43C at full load. I reckon I may even be able to lower this as I only used low grade thermal grease!!
Like I said, I'll post piccies as soon as poss.
I don't mind the PMs, although discussion should be conducted on the forum, but the content of the questions set an alarm bell ringing and as moderator I reckon I should lead by example.
Please, everyone who is contemplating a PSU mod, be aware that this is the one area of your PC that really should NOT be tampered with and any mods made to it should be made with extreme care.
I cannot stress enough that although I have cut away at the PSU casing in my SV24, the 80mm fan effectively shields all parts of the PSU internals that the discarded casing used to. The rest of my PSU casing remains intact and I do NOT advocate the full removal of the PSU casing.
Without getting into a big debate as to whether it is the current or the voltage which can do you harm, the fact remains that the PSU is plugged directly into the mains supply. Mess with this and make a mistake and you run the risk of a serious accident.
My apologies to anyone who finds the above deeply patronising, but to the people who have contacted me and told me they have removed their PSU casing PLEASE PLEASE BEAR THIS WARNING IN MIND.
The PSU fan is a problem, it's noisy and I didn't have much faith in either swapping it for a quieter 40mm fan or 7V-ing it. It shifts sod-all air in stock setup anyway. I was also unhappy with the way the PSU did not vent out of the case (as in later Shuttles) but simply recirculated the air within the unit. As you know, the SV24 relies on one 60mm fan and a few vents for it's entire air throughput.
Through a bit of fiddling I found that if I cut away at the PSU casing where the 40mm fan sat, I could sit an 80mm fan between the PSU and the case (a little bit of careful cable routing was required. The right hand side of the fan sat flush with the front of the case and the left edge sat perfectly level on the retainer clip of the first RAM clip.
With a fan blowing INTO the case, half the air blows across the PSU, providing cooling (don't rely on passive PSU cooling) and half the air blows across the case in the direction of the CPU. By using a low volume Papst fan (12dba) I achieved sufficient cooling for my C3 900Mhz even with a 7V-ed 60mm low volume Panaflo providing the exhaust. Heatsinking for the CPU comes from a chunky unbranded heatsink that I found for £2 on eBay. It fits in nicely with the low-profile PCI card I have at the moment but would be too tall for a full height card. If I ever install a more powerful CPU, I'd swap out the HSF for a Thermaltake Golden Orb.
As a bonus, the small bracket which normally retains the PSU, holds the 80mm fan in place perfectly. This combined with the fact that the fan fits perfectly flush with the edge of the chassis means that one 80mm hole, an aluminium mesh filter and some blowhole trim give a really nice 'stealth' finish with no need for extra external fan screws/fingerguards.
All the above combined with small rounded cables mean that I run at around 30C at idle rising to around 43C at full load. I reckon I may even be able to lower this as I only used low grade thermal grease!!
Like I said, I'll post piccies as soon as poss.