I have a question about CPU times!

Okay I was glancing at our group's table and here's my stats:

195) Xizer 4 16 hr 59 min 4 hr 14 min 48.7 sec

Now comparing it with others I noticed something peculiar:

196) penguin_assault 3 191 hr 53 min
197) marcus 3 138 hr 09 min

These 2 people right below me have completed only 3 results yet their CPU time is roughly 5-10 times that of mine. Why is this?

It depends on what your system contains. Someone with a 333mghtz processor will be a hell of alot slower than someone running a P4 3.06. It depends on the speed and memory.

Oh I see.

I have a Pentium 4 2.4 GHz processor with 512 MB of RAM. I didn't think it was that fast, but damn... it makes it look like I have some Uber-1337 computer from the future compared to those...

it also depends on what you are running at the same time as your work units. I can do a WU in under 4 hours if I just leave my pc to get on with it, but if I am playing a game then it has taken about 8 hours before. It will also take longer if it is set up to run as a screensaver instead of just running in the background.

Ahh, that must be it.

My computer can handle it running all the time so that's what I do. It can finish it in roughly 4 hours whilst I am doing my regular stuff (browsing the 'net, running AIM and windows media player). I haven't tried it while playing games.

[Edited on 2-15-2004 by EliteXizer]

Hi EXR!!

Again, coming to this discussion late (I'm not usually but it's been kind of hectic recently!)!!

The figures you quote seem about "right": my 2.6Ghz P4 with WinXP Home and 512 MbRAM takes about 4 hours on average to complete 1 WU. I run SETI@home client 3.08 constantly in the background incidentally. Times can change dependent on many factors but significant ones are:

a) The data in the WU itself: if corrupt data is detected eg because of locally rec'd RFI (radio frequency interference) captured at the same time at Arecibo, these results are "scrapped" but you still receive a "credit" for them ie it registers as a WU completed. This happens rarely in my experience but I have known a WU to be returned as completed after about 20 minutes!! However, some units contain *so much* data that processing takes longer - again, I've known units take up to 6 hours to process using the same platform. The resultant signals don't necessarily "look" any different it's just the processing seems to be more complex.

b) Local conditions: as others have written, much depends on what else is happening on your machine at the time, as SETI@home, whilst being very CPU-demanding, also releases the CPU readily if other programs or system resources need it (it is designed, afterall, to run in the background and not interfere with what you want the machine to do - S@h wouldn't gain many friends if it stopped you using your machine!! )

So, for example, when I use my machine for game playing, I might as well disable S@h, as effectively it goes to sleep until I've finished playing the game. However, programs like MSWord etc - and other "killer apps" - are so undemanding of CPU pwer that I never notice any significant difference in the cycle times of the WU's (there might be, but they are insignificant). But, as they say, "normal" apps are so dependent on our "slow" input (from my poor typing at least!) that the CPU simply gets "cracking" whilst waiting for that next input...

I hope this helps you EXR?

Okay, that helped.

Thanks.

and,
I started running Seti not long after it first started. Then, I had a Pentium 200mhz, running the screen saver version. The time to complete a wu was up there. Though I completed quite a few then because I had a bunch of machines going. Eventually, CPU speed increased, and I switched to the command line version. So, my average time is dropping but I'm only running it on one PC now.

Originally posted by Bob88
... but I'm only running it on one PC now.

*That*, of course, is about to change....!!