Alright, there was a request for some pics/info on my setup, thought I'd start a new thread so it didn't clog up some other thread. I'll put in some pics as thumbnails, but they're pretty slow to upload, be warned. Anyway, let's start with...
My HTPC, an NMeidaPC red wood case (more details here: http://www.newegg.com/Product/Product.aspx?Item=N82E16811204039
) with an i7-860, zalman cnps 9700 cooler, gts 250 card, windows xp. This case is cool, almost all wood, but it basically has one big 140mm fan in the back. The problem is that there's a shelf near the top for the hard drives, which limits the cpu heatsink height, that's why I went with the zalman cooler. Not the quietest cooler, but I cranked down the fan speed enough to get it to tolerable levels. That fix, along with a replacement of the fan with a 140 mm yate loon keeps it resonably quiet.
power use: 250W
Definitely not my most efficient machine, but I use it to record shows and play blu-rays, I don't want to add the 2nd gpu it would take to make it efficient. Maybe if they modify smp to use threads it will get more efficient.
This is a more recent build, a fortress ft-02, intel Q9300 @ 2.5GHz, nocuta nh-u12p cooler, dual gtx 260s, ubuntu linux. It's a nice case, but the heat coming out of the top is pretty intense. I really got it becaue it fits nicely into this ikea table leg/computer shelf.
My big system, a cosmos S case, intel Q9400 @ 2.66GHz, scythe mugen 2 cooler, gtx 295 and a gtx 725, ubuntu linux. I replaced most of the coolermaster fans with scythes and noctuas, I'm really surprised how quiet it is with the 295 and the 275 in it.
ppd/watt: 56 ppd/watt
My most efficient system, probably due to the gtx 295. One of these days I need to upgrade it to an i7, might wait for the 6 core ones to come out.
mod on side
A micro-atx system, a silverstone sg-01 with a q9550 at 2.83GHz, a low profile zalman cooler,a gtx285 with a thermalright hr-03 gtx heat sink on it, windows vista. My only attempt to go with a heat sink change on a card, it keeps the card cool enough to overclock a bit, but I had to cut a big hole in the side to put a fan on it. I originally bought the system from endpcnoise.com, but I added the card and upgraded it with the q9550 later.
ppd/watt: 42.9 ppd/watt
Another micro-atx system, the case is kind of like an apevia x-qpack but an older crappier version, picked it up on sale at Fry's one day on impulse, has an Atom 330 with an ION, a gts 250, ubuntu linux. A lower power system, but I've grown to hate the case, I might shut this one down when get into the top 500. Replaced the fans, but this case is so flimsy it's still pretty noisy.
Not bad, but not sure if it's worth the noise to keep it going.
My old htpc, a silverstone lc17 case (maybe an older variant), Q6700 dual core, noctua nh-u9? heatsink, 9600 gso, windows xp. This one is definitely getting shut down sometime soon, it's not wildy efficient. I originally also got this from endpcnoise.com, but swapped out the guts a while ago. Might move the previous Atom330/ION system into this case and ditch the crappy case.
One of my least efficient systems. Have to turn this off sometime.
My nas backup, a chenbro es34069 case, Atom 330, ubuntu linux, modded to have a 120mm fan blowing right down onto the cpu. This case is still a little noisy, but it is a nice form factor for holding 4 hard drives and a mini-itx board. Need to upgrade this thing one of these days, the original atom 330 boards are pigs, I'd love to see an intel culv on a mini-itx board.
My least efficient system, but it runs at low enough power that I'll probably keep it running. Maybe one day I'll transfer the hard drives to one of my more efficient systems and shut this thing down. Or get a more efficient motherboard for it.
Now this one is just an acer timeline notebook with a dual core cpu and windows 7. It runs the smp client pretty well, and it's really efficient. I only recently put a kill a watt on this thing and was amazed at the power consumption.
So that's what I have up and running now, as I said, when I get into the top 500 I'll probably shut a couple of these machines off, and drop back into the 60k or even 50k ppd range. And keep in mind, these ppd numbers are roughly best case numbers coming out of Fahmon, actual reported numbers are always a bit lower.