Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!sdd.hp.com!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!lll-winken!ncis.tis.llnl.gov!dog.ee.lbl.gov!nosc!crash!pnet01!lkoop From: lkoop@pnet01.cts.com (Lamonte Koop) Newsgroups: comp.sys.amiga.hardware Subject: Re: Slow GVP '030 accelerator board Message-ID: <5749@crash.cts.com> Date: 20 Nov 90 10:36:02 GMT Sender: root@crash.cts.com Organization: People-Net [pnet01], El Cajon CA Lines: 72 jma@beach.cis.ufl.edu (John 'Vlad' Adams) writes: >In article <1990Nov16.175346.4884@maverick.ksu.ksu.edu> yeewei@matt.ksu.ksu.edu (Yee-Wei Huang) writes: >> >>Amiga 2000HD >>Supra memory expansion board w 2meg 80ns ram >>GVP 3001 accel card w/o '882 and w/o 32 bit ram >> >> When I run performance tests on the machine, I show only a 20% >>increase over the stock 68000! I know that this card will perform much >>better with 32bit ram and a fpu, but it is clocked 4 times as fast as >>the stock 68000, and the 030 should perform better at the same clock >>speed. > >You are lucky to see that much of a performance boost. Don't >forget, the 030 fetches memory in four-byte chunks through >the normal Amiga bus. Therefore, you slow down with the wait >states and the double fetch. An 030 will not outperform the 68000 >without 32bit fast ram. No...he is correct in that something is wrong here. Yes, the 030 does longword instruction prefetches, and running on a 16-bit bus will cause a performance hit, but with the 030 caches active, he should be seeing performance around 2-2.5x that of a stock A2000. The instruction cache should 'buffer' some of the hit taken by the operations on the 16-bit bus. Without it, you are indeed correct that the 030 would act as if crawling in molasses. The 030 (and 020 for that matter) instruction caches are activated automatically by the OS during system startup, so I don't see where the cache should be off, so I would suspect a problem with the board. (Unless GVP is doing some odd way of hooking into the 16-bit bus that would result in only achieving this mediocre performance increase on that kind of setup, but I doubt it. > >>Another funny thing: all my system performance and monitering >>software tells me that I have an '020 instead of an '030. Anyway, if >>some one could either give me some suggestions as to what might be >>wrong, (or worst case tell me that 20% is all you get :-( ) I would >>be very thankful! >> >There is no magic flag to tell the difference via software between >an 020 and an 030. Do yourself a BIG favor. Get at least two >megs of 32bit ram. Don't worry about the FPU, as it won't >do anywhere near as much for you. There is indeed a 'magic flag' to tell the difference between the two processors. Unfortunately, AmigaOS 1.3 (and below) doesn't know how to use it. The 'flag' is found in the Exec base structure and can be read by referencing the Exec-->AttnFlags field. Bits within this field are set according to the type of processor/fpu on the system. AmigaOS 1.3 will properly identify a 68020/881 combination, but ID's a 68030/882 combo simply as the former. [AmigaOS 2.0 fixes this]. For a good example of how to ID the cpu properly under v1.3 or so, Dave Haynie's SetCPU source is what I'd recommend. Anyway, many programs that simply check this field will not be able to tell that a 68030 is in fact installed rather than a 68020. I'd recommend running Dave's SetCPU on the system with no arguments. It'll tell you what CPU is on the system (correctly...and will also set the 'magic' bits so that other programs will ID it properly as well...if they are programmed to do so). If SetCPU shows only a 68020, then I'd say there is something VERY wrong with this board. Also, SetCPU will allow you to fiddle with the caches, and will tell you how they are currently set. It would be prudent to be sure that the Instruction cache at the least was 'on'. >John M. Adams --**-- Professional Student on the eight-year plan! /// >Internet: jma@beach.cis.ufl.edu -or- vladimir@maple.circa.ufl.edu /// >"We'll always be together, together in electric dreams" Moroder & Oakey \\V// >Sysop of The Beachside. FIDOnet 1:3612/557. 904-492-2305 (Florida) \X/ --LaMonte UUCP: {hplabs!hp-sdd ucsd nosc}!crash!pnet01!lkoop ARPA: crash!pnet01!lkoop@nosc.mil INET: lkoop@pnet01.cts.com