blgardne@esunix.UUCP (Blaine Gardner) (12/05/88)
While there's been a lot of discussion on how badly DMA controllers are
slowed down by overscan and lots of bitplanes, I hadn't noticed any
slowdown on my system, so I ran disperfa with a variety of screens
displayed as frontmost.
At worst, there is a 10% slowdown for HAM and hires graphics. I don't
consider this significant since I've seen diskperfa r/w speed varations
of 10-20% on my own system (note the three timings for the 704x470
Workbench screen).
The manual for the A2090A notes that SCSI drive will suffer some slow
down, but that ST506 drives will show this to a lesser degree. I had
hoped for higher speeds than I'm getting, but on the bright side, speed
seems completely unaffected by anything else happening in the system.
Here are the diskperfa results for my system:
(Amiga 2000, 3M RAM, WB/KS 1.3, A2090A, ST4096 drive, FFS.)
Timings with a 640x400 Workbench screen.
File create/delete: create 7 files/sec, delete 43 files/sec
Directory scan: 94 entries/sec
Seek/read test: 96 seek/reads per second
r/w speed: buf 512 bytes, rd 62415 byte/sec, wr 27594 byte/sec
r/w speed: buf 4096 bytes, rd 131072 byte/sec, wr 104857 byte/sec
r/w speed: buf 8192 bytes, rd 174762 byte/sec, wr 124830 byte/sec
r/w speed: buf 32768 bytes, rd 218453 byte/sec, wr 145635 byte/sec
Timings with a 704x470 Workbench screen.
File create/delete: create 7 files/sec, delete 41 files/sec
Directory scan: 91 entries/sec
Seek/read test: 96 seek/reads per second
r/w speed: buf 512 bytes, rd 62415 byte/sec, wr 27594 byte/sec
r/w speed: buf 4096 bytes, rd 131072 byte/sec, wr 104857 byte/sec
r/w speed: buf 8192 bytes, rd 174762 byte/sec, wr 124830 byte/sec
r/w speed: buf 32768 bytes, rd 218453 byte/sec, wr 145635 byte/sec
File create/delete: create 9 files/sec, delete 23 files/sec
Directory scan: 41 entries/sec
Seek/read test: 94 seek/reads per second
r/w speed: buf 512 bytes, rd 62415 byte/sec, wr 27306 byte/sec
r/w speed: buf 4096 bytes, rd 124830 byte/sec, wr 104857 byte/sec
r/w speed: buf 8192 bytes, rd 174762 byte/sec, wr 124830 byte/sec
r/w speed: buf 32768 bytes, rd 218453 byte/sec, wr 137970 byte/sec
File create/delete: create 9 files/sec, delete 23 files/sec
Directory scan: 38 entries/sec
Seek/read test: 95 seek/reads per second
r/w speed: buf 512 bytes, rd 60963 byte/sec, wr 27306 byte/sec
r/w speed: buf 4096 bytes, rd 131072 byte/sec, wr 104857 byte/sec
r/w speed: buf 8192 bytes, rd 174762 byte/sec, wr 124830 byte/sec
r/w speed: buf 32768 bytes, rd 238312 byte/sec, wr 145635 byte/sec
Timings with a 320x200x6 HAM image displayed.
File create/delete: create 9 files/sec, delete 22 files/sec
Directory scan: 38 entries/sec
Seek/read test: 86 seek/reads per second
r/w speed: buf 512 bytes, rd 60963 byte/sec, wr 27594 byte/sec
r/w speed: buf 4096 bytes, rd 131072 byte/sec, wr 100824 byte/sec
r/w speed: buf 8192 bytes, rd 174762 byte/sec, wr 119156 byte/sec
r/w speed: buf 32768 bytes, rd 218453 byte/sec, wr 145635 byte/sec
Timings with a 320x400x6 HAM image displayed.
File create/delete: create 9 files/sec, delete 22 files/sec
Directory scan: 38 entries/sec
Seek/read test: 87 seek/reads per second
r/w speed: buf 512 bytes, rd 60963 byte/sec, wr 27594 byte/sec
r/w speed: buf 4096 bytes, rd 131072 byte/sec, wr 100824 byte/sec
r/w speed: buf 8192 bytes, rd 174762 byte/sec, wr 124830 byte/sec
r/w speed: buf 32768 bytes, rd 218453 byte/sec, wr 145635 byte/sec
Timings with a 640x400x4 hires image displayed.
File create/delete: create 6 files/sec, delete 14 files/sec
Directory scan: 23 entries/sec
Seek/read test: 56 seek/reads per second
r/w speed: buf 512 bytes, rd 35424 byte/sec, wr 24272 byte/sec
r/w speed: buf 4096 bytes, rd 119156 byte/sec, wr 87381 byte/sec
r/w speed: buf 8192 bytes, rd 163840 byte/sec, wr 104857 byte/sec
r/w speed: buf 32768 bytes, rd 218453 byte/sec, wr 137970 byte/sec
All timings done by Blaine Gardner, 4 December 1988.
--
Blaine Gardner @ Evans & Sutherland 580 Arapeen Drive, SLC, Utah 84108
Here: utah-cs!esunix!blgardne {ucbvax,allegra,decvax}!decwrl!esunix!blgardne
There: uunet!iconsys!caeco!pedro!worsel!blaine (under construction)
"Nobody will ever need more than 64K." "Nobody needs multitasking on a PC."