dma or no dma?

SimeonArt

Member
Aug 2, 2000
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okay, here is my question. my system seems to run better with dma turned off for the harddrive; it's not as sluggish. should it be the other way around? however, my hdtach scores are low with dma turned off. is there something i'm missing. (my hdtach scores aren't too good with dma turned on, around 37mbps burst read speed, or something like that, when turned off, around 4-5mbps burst read speed)

ibm 75GXP 30g
abit kt7 (non-RAID)
duron 700 @ 950
plextor 8-4-32
toshiba dvd-rom
CL GeForce2
TurtleBeach Montego II
3com network card

any input would be appreciated.


 

GD695372

Senior member
Oct 24, 2000
386
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It should run faster with dma enabled, and might seem sluggish merely because of the increased cpu useage. I'd stick with whatever seems to perform the best in reality though, if I were you.
 

Wuming

Golden Member
Dec 14, 2000
1,030
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usually we are asked to turn on dma for cdrom and dvdrom and even cd writer. hmm... i never heard any advice about turning dma on for harddisks... should we?
 

ArchAngel777

Diamond Member
Dec 24, 2000
5,223
61
91
Simeon... I find this strange.. but I noticed this even before you posted it.... I have a similar setup... Your right the system is more sluggesh.. in games especially..

MY advice is install WINME... then put read ahead in device manager for teh HD, then enable DMA, and then add more memmory (I have 384) DMA gives me a higher score in synthetic benchmarks... but like i said.. in games and other things.. he is right it is more sluggesh... BTW to the guy below me... DMA has always been a feature for the hard drives since IDE..... it is a MUST for most users.. however for KT7... it may not be the best... I think when DMA is check the access time INCREASES... :-(


AMD 1.1 Ghz
Abit KT7-Raid
384 MB PC133 CAS 2
20.5 Gig HD
Geforce 2 GTS
SB live!
 

luv2chill

Diamond Member
Feb 22, 2000
4,611
0
76
What is your OS? Do you have Via's drivers installed? DMA should always give higher performance if your disks support it.

l2c
 

jpprod

Platinum Member
Nov 18, 1999
2,373
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Without DMA transfers ebabled, any heavier HDD activity leads to over 80% peak CPU utilization, whereas DMA mode brings that figure down to ~5%. Also, peak transfer rates are much higher in any modern DMA mode (UDMA/33, UDMA/66 or UDMA/100) than the fastest non-DMA mode (PIO/4, 16.7MB/s). I advice you to keep the DMA enabled and look into why it doens't work properly rather than disabling it.
 

SimeonArt

Member
Aug 2, 2000
43
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0
To answer a few questions:
I am using windows98 SE with the 4.26 VIA 4in1 drivers installed. I have 256M PC100 memory. I mean I wish I could find the problem, I especially wish I could try a different motherboard but I don't have the money for that right now. I've asked about this problem here before but never got much input. If you think of anything else let me know. thanks again

 

ArchAngel777

Diamond Member
Dec 24, 2000
5,223
61
91
Simeon, first of all, all motherboards glitch with the harddrive in games (all you power users, please dont come in here and BS about how yours does not, it does, and i know it) However some motherboards and hardrives do a better job at smoothing that out.

I have yet to see any computer run the X-Isle demo without some sort of glitch for a split second or for that matter run UT opening demo without a glitch for a sec, unless of course you modifed your cache setting for UT.
 

miniMUNCH

Diamond Member
Nov 16, 2000
4,159
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Mine glitches too in UT opening demo...just once for a fraction of a second...humm!? I haven't noticed sluggish performance from my hard drive though.

 

SimeonArt

Member
Aug 2, 2000
43
0
0
archangel:
I know all computers glitch sometimes, but that's not what i'm talking about. as it is now, with dma enabled, everything on my computer is sluggish including my mouse, winamp, etc. And anyway, my harddrive should be getting better scores in hdtach than it is according to all of these other peoples scores. Again, I'm not expecting my computer to be a super computer or anything, i'm just trying to figure out why it is so sluggish all the time, not just in games and when i'm doing graphics intensive stuff. thanks anyway though