larry@nstar.uucp (Larry Snyder) (06/30/90)
I've been tuning my kernel (386/ix 3.2 2.2 release) and running
a benchmark from MIPS - and the results are interesting:
CONTROLLER: ADAPTEC 1542A DRIVE: MINISCRIBE 9380S
MOTHERBOARD: 25MHZ '386 SOYO RAM: 8 MEGS 80 NS 32 BIT ON MOTHERBOARD
BUSS SPEED 12.5M 12.5M 12.5M 12.5M 8MHZ 12.5M
DMA SPEED 5MHZ 6.7M 8M 8M 8M 8M
BUSS ON/OFF 9/5 9/5 9/5 5/9 10/4 10/4
DD_1M1K 238K 284K 213K 223K 205K 223K
DD_1M2K 244K 180K 238K 277K 190K 116K
DD_1M8K 197K 277K 190K 330K 197K 256K
DD_1M17K 201K 277K 277K 218K 186K 190K
DD_5M1K 368K 274K 322K 351K 353K 351K
DD_5M2K 348K 348K 363K 385K 318K 314K
DD_5M8K 376K 348K 328K 376K 346K 356K
DD_5M17K 358K 371K 388K 385K 288K 478K
CP_1M 445K 488K 465K 465K 284K 539K
CP_2M 465K 460K 460K 418K 386K 436K
CP_5M 483K 476K 478K 459K 408K 427K
DISK-1T1X_RD 190K 293K 301K 201K 353K 379K
DISK-1T1X_WR 1280K 1280K 1280K 1280K 1280K 1280K
DISK-1T1X_RW 155K 155K 155K 153K 153K 153K
DISK-4T1X_RD 341K 379K 338K 369K 282K 286K
DISK-4T1X_WR 250K 261K 264K 254K 139K 277K
DISK-4T1X_RW 77K 76K 75K 75K 72K 77K
DISK-10T1X_RD 358K 359K 400K 366K 344K 372K
DISK-10T1X_WR 127K 98K 98K 106K 70K 121K
DISK-10T1X_RW 62K 62K 62K 61K 61K 62K
DISK-1T2X_RD 341K 366K 488K 476K 455K 500K
DISK-1T2X_WR 1463K 1463K 1463K 1463K 1463K 1463K
DISK-1T2X_RW 211K 213K 211K 209K 207K 213K
DISK-4T2X_RD 379K 374K 404K 367K 343K 392K
DISK-4T2X_WR 212K 218K 204K 212K 123K 247K
DISK-4T2X_RW 74K 74K 74K 73K 70K 75K
DISK-10T2X_RD 376K 382K 387K 332K 329K 377K
DISK-10T2X_WR 119K 123K 116K 120K 72K 124K
DISK-10T2X_RW 61K 61K 61K 60K 60K 62K
I will be posting the benchmark to the net later this evening
(posting only to comp.unix.i386) and am looking forward to feedback
from others running this controller with ISC 2.2.
--
Larry Snyder, Northern Star Communications, Notre Dame, IN USA
uucp: iuvax!ndmath!nstar!larry -or- larry@nstar
Public Access Unix Site (219) 289-3745 / lots of files & free PEP feeds!behm@zds-ux.UUCP (Brett Behm) (07/04/90)
In article <1990Jun29.230754.251@nstar.uucp>, larry@nstar.uucp (Larry Snyder) writes: > I've been tuning my kernel (386/ix 3.2 2.2 release) and running > a benchmark from MIPS - and the results are interesting: Interesting is an understatement. > CONTROLLER: ADAPTEC 1542A DRIVE: MINISCRIBE 9380S > MOTHERBOARD: 25MHZ '386 SOYO RAM: 8 MEGS 80 NS 32 BIT ON MOTHERBOARD > > > BUSS SPEED 12.5M 12.5M 12.5M 12.5M 8MHZ 12.5M > DMA SPEED 5MHZ 6.7M 8M 8M 8M 8M > BUSS ON/OFF 9/5 9/5 9/5 5/9 10/4 10/4 > > DD_1M1K 238K 284K 213K 223K 205K 223K A DMA Speed of 8 holding bus on/off a constant is slower than 5 and 6.7? > DD_1M2K 244K 180K 238K 277K 190K 116K Wouldn't you think making a 2K transfer would be faster than a 1K. All the overhead associated with setting up the read like arbitration, selection, message out and in, commands, and status should be cut in half. Unless of course the driver is kicking in some sort of read ahead, then no difference would be expected. 6.7 took a 100K hit - isn't that odd? 8 at 10/4 is half as fast? > DD_1M8K 197K 277K 190K 330K 197K 256K > DD_1M17K 201K 277K 277K 218K 186K 190K More unexplainable randomness. > DD_5M1K 368K 274K 322K 351K 353K 351K With 1M, 6.7 was the fastest, now it is the slowest with 5M. Why would transferring 5M in 1K chunks be any faster or slower than 1M ? > DD_5M2K 348K 348K 363K 385K 318K 314K > DD_5M8K 376K 348K 328K 376K 346K 356K > DD_5M17K 358K 371K 388K 385K 288K 478K > CP_1M 445K 488K 465K 465K 284K 539K > CP_2M 465K 460K 460K 418K 386K 436K > CP_5M 483K 476K 478K 459K 408K 427K More strangeness, but less variance I guess. > I will be posting the benchmark to the net later this evening > (posting only to comp.unix.i386) and am looking forward to feedback > from others running this controller with ISC 2.2. I guess I would conclude here by saying that the above data doesn't follow any pattern or make intuitive sense. Was there anything else running with the benchmark? My studies with the adaptec 1542A show a typical 1K data transfer to take around 4.8 msec of overhead + access time + dma transfer time. (this assumes that the mailbox for the drive is not starved - at least 1 command pending ) Since most drivers run the adaptec in async mode, the best transfer time we would expect is around 2 MB/sec. 1K would take around .5 msec, but actual traces show about .7 msec. Assuming the files you are reading are sequentially laid out on the disk, the only seek we would encounter is for the very first transfer. This would give a flat out rate of 4.8 msec + .8 or 5.6 msec per 1K data transfer - 178K/sec. So the driver must be performing some sort of read ahead. From what data I have gathered, DMA rate and BUSON/BUSOFF tunes really don't matter that much; I suppose they might become more significant as more bus master dma's were placed on the bus (like another adaptec card). I really doubt they can make any more than a 1-2% improvement given a loaded system doing primarily random access. I really do not know what to make of these results. Brett Behm