SETI performance questions

[Unforgiven]

ok ive got a bunch of questions here that i would like all of your input on...

1) how much does the speed of your ram really effect your time? i switched from pc100 to ddr2700 on a machine that could take both types of ram and my crunch time went down 40-45 minutes per unit. coincidence or is there really something to this?

2) how much does the amount of ram effect your time? i mean if seti only uses about 16 megs of ram, does it matter if you have 1 gig or 512 megs?

3) how much of a role does the speed of your hard drive play in your seti crunching? is it a non-factor? im assuming it wont matter at all or if it does, the difference will be minimal. i know seti writes to the hard drive every so often so i just thought i would ask this to see if there is any gain/loss based on hd speed.

i know these may seem like stupid questions but its just something ive been curious about for awhile and would like to know if anyone has any insight to these. my questions are based off using the cli and not the gui version of seti if that makes any difference.

thanks in advance,
plankton

 

[Zbox]

the huge drop in crunch time is a result of the change in architecture from the 168 pin pc100 to 184 pin ddr memory (it's faster, more efficient, has bigger pipelines to push data thru, etc). I was very skeptical of those motherboards when they first came out.... I guess they make sense for economical reasons, but obviously you will take performance hits for utilizing aged ram technology.

on the whole, the amount of ram you have has a very small influence over crunch time. provided you have enough and you're not overloading your system with too many other processes, you should be okay.

as far as hard drive speed altering your crunching... sure it's a factor, but one i would consider negligible. your client spends the vast majority of it's time crunching, and not writing to and reading from the hard drive.

hope this helps a litttle

 

[Smoke]

Sounds to me that Zbox has nailed this one.

Smoke waves at Mentee plankton.

 

[Unforgiven]

daddy?

 

[Unforgiven]

yeah zbox that is what i was kind of expecting and was thinking but i just wanted to know if i was right in my assumptions. thank you for the speedy reply and in detail description

 

[Vich]

Nice reply zbox, on the issue of hard drives i disagree and think that Hd are an even less of a factor, since even ata 66 hardly saturates all its bandwitch under full load!

 

[Assimilator1]

Yep Zbox pretty much has it
I'll add a few bits though

1.Yep! ,
ok seriously ,I've found on an Ath XP/Duron rig on PC133 RAM(133FSB) switching to DDR RAM knocks about 1/2hr off WU time.
Having low latencies also cuts down WU times ,not so much but it's still worth about 10mins or so on the same rig mentioned.

2.Nothing to add here

3.HDD speed makes virtually no difference ,many moons ago I had a Cel 300@464 ,it started off with a 540Mb HDD ,when I switched it to a 20GB HDD I saw no change in WU time

Btw not stupid questions at all
Lol @ 'daddy?'

 

[Unforgiven]

yeah what i was thinking of on the hard drive front was rotational speed of the hard drive, such as scsi/sata compare to say a 5400 rpm hd. also the question of ide bus speed from ata 66/100 is a something else i was pondering.

 

[Jalapeno]

I have switched from a 7200 ATA133 to a 10000 SATA 150 harddrive and the rest of the system stayed the same. The difference?

None.

 

[yelo333]

Originally posted by: Jalapeno
I have switched from a 7200 ATA133 to a 10000 SATA 150 harddrive

Then, why does your system rig page mention that you have a 7200 rpm drive? Maybe that page is a joke... I've never seen a service pack for win 3.1, nor a second edition(unless you mean 3.11).

 

[Jalapeno]

Originally posted by: yelo333

Originally posted by: Jalapeno
I have switched from a 7200 ATA133 to a 10000 SATA 150 harddrive

Then, why does your system rig page mention that you have a 7200 rpm drive? Maybe that page is a joke... I've never seen a service pack for win 3.1, nor a second edition(unless you mean 3.11).

OK,OK, I have not been here in years. I will update it soon...

 

[Ronin]

ROFL. That's funny You will see a difference in WU production, but the HD speed isn't going to make a ton of difference.

 

[Jalapeno]

Done.

 

[Silverthorne]

Does it speed up work unit times if you run the kernel in ram on a win XP machine?

 

[Wiz]

Going from a small cache 60gig maxtor to a 8meg cache 80gig WD drive greatly speeds up windows start up & app loading but wont help much once the app is in memory.
I built a pc for a friend with the 80 gig 8meg cache drive, fastest loading WinXP I ever saw

 

[kamper]

since we're getting all techie about the drives I'll add one more thing: if all seti is doing is writing to files then hard drive performance will not matter at all since write calls are nonblocking (data is cached, seti goes about it busines, data is written later). If, on the other hand, it opens and reads a file before writing then its a simple drive latency issue (data bandwidth doesn't matter, if it's not being used up) and performance would slow down. Except that, as everyone says, it doesn't happen often enough to make a noticeable difference.