erast1@unix.cis.pitt.edu (Evan R Aussenberg) (02/04/91)
In article <1991Feb03.210343.18244@chinet.chi.il.us> les@chinet.chi.il.us (Leslie Mikesell) writes: >I haven't done any formal timing but the general feeling I get is that >VP/ix disk operations tend to be faster than native DOS due to the >better performance of the unix disk cache. >Les Mikesell > les@chinet.chi.il.us I've been using pkunzip alot under ISC/VPix lately. While the program seems to work at the same speed as native DOS, writing to our Micropolis 320meg scsi is noticably slower than if I access the DOS partition via native DOS. This was true even if I was the only login. In fact, I installed some commercial software (about 10megs worth) on the dos partition by booting DOS from floppy because disk writing seemed faster to me than doing the same from VPix. Any comments? For your reference, the computer is an Intel model 302, 25mhz, 8meg. BTW- the above is not true when VPix is writing to the unix partitions. Evan -- Evan Ron Aussenberg erast1@unix.cis.pitt.edu IN%"erast1@pittunix"
les@chinet.chi.il.us (Leslie Mikesell) (02/07/91)
In article <87004@unix.cis.pitt.edu> erast1@unix.cis.pitt.edu (Evan R Aussenberg) writes: >I've been using pkunzip alot under ISC/VPix lately. While the >program seems to work at the same speed as native DOS, writing >to our Micropolis 320meg scsi is noticably slower than if I access >the DOS partition via native DOS. This was true even if I was >the only login. In fact, I installed some commercial software >(about 10megs worth) on the dos partition by booting DOS from >floppy because disk writing seemed faster to me than doing the >same from VPix. >Any comments? For your reference, the computer is an Intel >model 302, 25mhz, 8meg. On mine, there is only a slight difference, but I'm running a Conner IDE drive which has on-board buffering. Perhaps you are close to missing the interleave on the disk and the overhead of VP/ix is enough to miss and require another disk revolution. Les Mikesell les@chinet.chi.il.us
erast1@unix.cis.pitt.edu (Evan R Aussenberg) (02/07/91)
In article <1991Feb07.011850.19550@chinet.chi.il.us> les@chinet.chi.il.us (Leslie Mikesell) writes: |[I say]: | >writing [ with VPix & ISC ] to our Micropolis 320meg scsi is | >noticably slower than if I access the DOS partition via native DOS... | >For your reference, the computer is an Intel model 302, 25mhz, 8meg. |On mine, there is only a slight difference, but I'm running a Conner |IDE drive which has on-board buffering. Perhaps you are close to |missing the interleave on the disk and the overhead of VP/ix is |enough to miss and require another disk revolution. |Les Mikesell |les@chinet.chi.il.us The Micropolis we have is a voice coil hd with on-board cache as well. The interleave of the whole drive is 1:1 because our adaptec scsi board supports it. It may well be that the drive is too fast at 1:1 for VPix. I don't think you can change the interleave of a partition? The slowdown is typically in the writing. Reading the DOS partition under VPix is at least as fast as naitive DOS. On a semi-related note. The adaptec 154xB scsi board we have supports synchronous data transfers to/from its peripherals. The Mircropolis drive has a jumper which puts it in "synchronous mode" if available (that's the best I gather from the docs). Is there any way to know for sure that the two are talking synchronously? Also, how high has anyone set the transfer rate on the adaptec board. From memory, I think I put the shunt on the 6.x transfer rate. (It goes to 10ish I think). Thankyou for all the replies, here and email. For those interested, my email replies have concurred with the public posts. Evan -- Evan Ron Aussenberg erast1@unix.cis.pitt.edu IN%"erast1@pittunix"
larry@nstar.rn.com (Larry Snyder) (02/08/91)
erast1@unix.cis.pitt.edu (Evan R Aussenberg) writes: >Also, how high has anyone set the transfer rate on the adaptec board. >From memory, I think I put the shunt on the 6.x transfer rate. >(It goes to 10ish I think). those jumpers don't matter - the transfer rate is set in the kernel which overrides the jumpers on the board -- -- Larry Snyder, NSTAR Public Access Unix 219-289-0287 (HST/PEP/V.32/v.42bis) regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar!larry, larry%nstar@iuvax.cs.indiana.edu}
allbery@NCoast.ORG (Brandon S. Allbery KB8JRR) (02/10/91)
As quoted from <87004@unix.cis.pitt.edu> by erast1@unix.cis.pitt.edu (Evan R Aussenberg): +--------------- | I've been using pkunzip alot under ISC/VPix lately. While the | program seems to work at the same speed as native DOS, writing | to our Micropolis 320meg scsi is noticably slower than if I access | the DOS partition via native DOS. This was true even if I was | the only login. In fact, I installed some commercial software | (about 10megs worth) on the dos partition by booting DOS from | floppy because disk writing seemed faster to me than doing the | same from VPix. +--------------- This depends on the implementation. If the DOS filesystem is emulated by VP/ix, then it'll be slow. If a DOS filesystem type has been added to the kernel via the File System Switch mechanism (SCO supports this, at least under SCO UNIX) then you get fast access... and you can mount the DOS partition and use it from UNIX as well. (Arguably, a silly thing to do.) It also depends on whether the VP/ix code uses the UNIX disk cache (it's not dependent on UNIX file systems, at least on the systems I've used) or the "raw" device. ++Brandon -- Me: Brandon S. Allbery VHF/UHF: KB8JRR on 220, 2m, 440 Internet: allbery@NCoast.ORG Packet: KB8JRR @ WA8BXN America OnLine: KB8JRR AMPR: KB8JRR.AmPR.ORG [44.70.4.88] uunet!usenet.ins.cwru.edu!ncoast!allbery Delphi: ALLBERY
tmh@bigfoot.FOKUS.GMD.DBP.DE (Thomas Hoberg) (02/19/91)
In article <88612@unix.cis.pitt.edu>, erast1@unix.cis.pitt.edu (Evan R Aussenberg) writes: |> In article <1991Feb07.011850.19550@chinet.chi.il.us> les@chinet.chi.il.us |> (Leslie Mikesell) writes: |> |> |[I say]: |> | >writing [ with VPix & ISC ] to our Micropolis 320meg scsi is |> | >noticably slower than if I access the DOS partition via native DOS... |> |> | >For your reference, the computer is an Intel model 302, 25mhz, 8meg. |> |> |On mine, there is only a slight difference, but I'm running a Conner |> |IDE drive which has on-board buffering. Perhaps you are close to |> |missing the interleave on the disk and the overhead of VP/ix is |> |enough to miss and require another disk revolution. |> |> |Les Mikesell |> |les@chinet.chi.il.us |> |> The Micropolis we have is a voice coil hd with on-board cache as |> well. The interleave of the whole drive is 1:1 because our adaptec |> scsi board supports it. It may well be that the drive is too fast |> at 1:1 for VPix. I don't think you can change the interleave of |> a partition? I did once on an MFM drive. 2:1 was ideal for DOS, but Micoport Unix 286 was too slow for that. So I wrote a small Turbo Pascal program and reformatted the Unix partition 3:1. Once Microport added RLL support, an Adaptec 2372 made it at 1:1. I don't think you can and in any case you wouldn't want to do that on a SCSI drive. |> |> The slowdown is typically in the writing. Reading the DOS partition |> under VPix is at least as fast as naitive DOS. |> I don't think it's interleaving but ISC's super careful approach to writing on a DOS file system. It's not a VPIX problem but a DOS-file-system problem as writing times deteriorate just as badly when the writing is done via Unix. VPIX talks to Unix for all file i/o and cannot tell a DOS partition from a Unix file system. I had planned to back up my DOS partitions under UNIX with a streamer. Backing up is no problem, but the restores are too slow to be useful. I believe that ISC immediately writes back any changes to the FAT and all data blocks. This incurrs lots of seeks for every data block written and causes write rates to drop below floppy values. Since changing this behavior for the DOS file system seems to be a major effort the only solution here is to use the Unix file system even under VPIX, but then some people need to use native DOS on their data, too... |> On a semi-related note. The adaptec 154xB scsi board we have supports |> synchronous data transfers to/from its peripherals. The Mircropolis |> drive has a jumper which puts it in "synchronous mode" if available |> (that's the best I gather from the docs). Is there any way to know |> for sure that the two are talking synchronously? |> Roy Neese's SCSI tools will tell you. For me sync vs. async changed the performance from 1295KB/s to 1300KB/s, so it's not really worth it. You should not set the sync mode on both the Adaptec and the drive as least if the 'sync' jumper on the drive means 'negociate for sync mode' rather than 'enable sync mode'. That would cause conflicts. |> Also, how high has anyone set the transfer rate on the adaptec board. |> From memory, I think I put the shunt on the 6.x transfer rate. |> (It goes to 10ish I think). |> According to what I remember from one of Roy's comments, 6.7 MB is considered ideal. By the way, the best tool I found to measure the effects of all that jumpering and bus tuning is called 'bonnie'. I am quite happy to be faster in all cases than a Sparc 470... |> |> Evan |> -- |> Evan Ron Aussenberg |> erast1@unix.cis.pitt.edu |> IN%"erast1@pittunix" --tom ---- Thomas M. Hoberg | UUCP: tmh@bigfoot.first.gmd.de or tmh%gmdtub@tub.UUCP c/o GMD Berlin | ...!unido!tub!gmdtub!tmh (Europe) or D-1000 Berlin 12 | ...!unido!tub!tmh Hardenbergplatz 2 | ...!pyramid!tub!tmh (World) Germany | BITNET: tmh%DB0TUI6.BITNET@DB0TUI11 or +49-30-254 99 160 | tmh@tub.BITNET
marz@cbnewsb.cb.att.com (martin.zam) (02/20/91)
:From: les@chinet.chi.il.us (Leslie Mikesell) : :>I've been using pkunzip alot under ISC/VPix lately. While the :>program seems to work at the same speed as native DOS, writing :>to our Micropolis 320meg scsi is noticably slower than if I access :>the DOS partition via native DOS. This was true even if I was :>the only login. In fact, I installed some commercial software :>(about 10megs worth) on the dos partition by booting DOS from :>floppy because disk writing seemed faster to me than doing the :>same from VPix. : :>Any comments? For your reference, the computer is an Intel :>model 302, 25mhz, 8meg. : :On mine, there is only a slight difference, but I'm running a Conner :IDE drive which has on-board buffering. Perhaps you are close to :missing the interleave on the disk and the overhead of VP/ix is :enough to miss and require another disk revolution. : :Les Mikesell : les@chinet.chi.il.us : When I run Norton Advanced v4.5 on my 33Mhz 386 with 320Mbyte ESDI, I get the following figures: PURE DOS 4.01 VPIX under UNIX CI = 39.7 CI = 34.3 DI = 21.5 DI = 332.5 PI = 33.6 PI = 133.7 I figure the difference in Computing Index (CI) accounts for emulation overhead. The difference in Disk Index (DI) may indicate that all of my C: drive fits into UNIX buffer cache. The Performance Index (PI) indicates the composite throughput. Anybody else with interesting performance stats? Martin Zam (201)564-2554