If someone knows differently, say so but I don't think there is any way to control what size WUs you get. I don't even think that it is known beforehand. There has to be some problem with your machine. It is hard to tell from what you have said. I would not be surprised if it is a heat related problem of some sort. Try opening the cover and putting a small fan blowing cool air into the case. ... Just a guess.

I think I just got the mother of all work units (WU). Just to do 1% took just about an hour. Now at 12 hours and 38 minutes I am now at 12.8% My computer has an Intel P4 3.20E ghz 478 pin 800 mhz FSB processor, 2 512 mb PC 3200 400 mhz Kingston single channel memory modules (1 gig total) and a 250 gb Hitachi IDE ata/100 hard drive (with 10 gb allocated for this project). At 100% CPU usage my CPU tempature is about 119F so overheating is not an issue (lots of cooling fans). I guess right now the work units being handed out are really large. Perhaps the processor or memory demands of these work units might be more than some systems can handle.

Thank you all for your sage and helpul advice, but my friend appears to have solved the problem with uninstall/reinstall and re-registration. It was not so much the size of the WU that troubled him, more the fact of his PC locking up solid after a while. The latest download is running at 18.3% after 2 hours 17 minutes, further and faster than ever before. So, let us trust that the matter is resolved.

To the member suffering computational constipation, I would advise 'more' fibre, not less. Failing which, try Ex-Lax.

As far as I can tell, they are not allocated on processing power otherwise we would be getting pretty much the same WU all the time.

For example, I have had days where I have completed 4 WU's due to their size/complexity and days (such as the last couple) where I have received WUs that take more than 24 hours (up to 40 hours) to complete.

Also, there is no real way to do this if you have more than one device install unless there was some processing done at the WCG servers before allocation which would make the whole computing power of the servers much greater.

I just did some calculations. On my present WU it is going to take just over 160 hours of processing to complete the WU. I have done 80 WU's so far and none even came close in processing time to this one. All others were in the 24 hour and shorter range. From the graphic of the protein, it is not a very large one compared to past WU's.