I have both E5450s in the rig and folding away at 3.4ghz (up from 3ghz). I had a straight out crash when I pushed for 3.6ghz and a blue screen after half an hour of folding near 3.5ghz. So I am leaving it 3.4 for now which seems rock solid stable.
Jury is out on PPD at the moment, I had a initial estimate of 20k when running at 3ghz but, didn't really let it settle for long enough for a proper conclusion (am running a older V7 client on this dirty Vista instal) and since the blue screen a good few hours ago the PPD is settling down, at 29.5k PPD at the moment and it has been slowly dropping from 35k for the past 3 hours... So I guess around 26k for the current WU at the current clock speed.
Edit: Progress on the XW6400/XW6600 hybred.
So, the rig froze again, this time while running at 3.4ghz, took a fair few hours though. Its currently running stock to make sure it wasn't something else causing the freeze.
So far, not much progress... but it's getting there. I drilled some holes in the DVD:RW case so that the drive can sit back a little further in the case and I have one of the case drive bay blanks atatched to the front to hid the drive from view, for no other reason than the case is black and the drive is not. That has been fairly successful.
Less successful is my quest to add more wires to the PSU as the standard PSU is rather lacking in that department even though it has a high wattage. Some may remember I did this previously to my XW6400 PSU. This time the donor PSU is also lacking in wires. An old 300w random thing that came out of a cheap case. It has a 24 pin mobo connector and one 'P4' 4 pin wire but no PCI-E connector. I wasn't really expecting one (just like last time) but there is only one single molex string thats really long enough and it has some random SATA connectors on there too.
So I have stripped that PSU, grabbed the wires and screws and binned the rest, not sure how I will move forward on this one. I might take some wires off the mobo connector if they are long enough. I might have to combine some wires (solder and cover in heat shrink). I might just take the molex connectors and use some wire (that I will have to find) to make what I need... Either way it's going to be a pain but I need the extra wires added for the 460 GTX otherwise the wires are stretched and all over the place looking like a mess, and we can't have that now, can we.
Last but not least, I need to sort out an IDE connector for the DVD drives. If I had enough spare cash I'd just throw in an SATA drive and be done with it, but I'd rather use what I already have. The XW6400 came with an IDE DVD drive and I added my old IDE NEC DVD:RW (just as it was when running the XW6400 mobo).... My dad taking claim of the SATA DVD:RW that came with the bare bones XW6600 we got. The IDE cable wouldn't be a problem if HP in their infinite wisdom hadn't moved the IDE port from the side of the board to the very bottom. I have a standard flat wire that should be long enough but will restrict airflow directly into the CPU heatsinks, I have a round wire which I don't think is long enough to reach both drives.
While I was doing all the faffing the computer was folding and is doing so now as I take a break from all the fiddling and shouting at the dog to get off of everything. Hopefully the rig will be all done by close of day tomorrow (or today UK time) unless I need to do some computery bits shopping... which I really don't want to have to do!