t68@nikhefh.nikhef.nl (Jos Vermaseren) (10/01/90)
With all the ongoing bickering about Atari policy I think it is about time that someone should mention that the TT is actually quite a nice machine. At the moment I have at home a TT with: 32 Mhz 68030 32 Mhz 68882 4 Mbytes ST RAM 4 Mbytes TT RAM 48 Mbytes 28msec hard disk VGA monitor (640 by 480 pixels with 4 color planes). So of course I had to test its performance and the like. It turns out that the performance seems to be disappointing till you tune it the same way many people got their ST tuned with cachexxx.prg and/or similar programs. The speed is very much a function of what memory you use, as can be seen in the table: On Mega 4: 249 sec ST/RAM 68030 Cache off 146 sec TT/RAM 68030 Cache off 86 sec ST/RAM 68030 Cache on 80 sec TT/RAM 68030 Cache on 55.5 sec TT/RAM 68030 Cache on 68020 code 51.4 sec The above was a FORM test program. Typical runs give about a factor 4. I measured the same kind of speed increase for the turbo C compiler. After turning on the appropriate bits in the program header to force the compiler to run in the TT RAM the speed increase was more than a factor 4. MetaFont runs faster by a factor 8. Apparently it uses many shifts and bitfields. Of course many programs don't run on it, but it is possible to switch to ST mode (choice of all three resolutions). The main problem for me is that the Turbo-C compiler doesn't support the 68020 modes convincingly. Especially when long multiplications divisions and mod operations are involved it may loose track of what it is doing. It is also necessary to use a new floating point library. The 68882 operations are produced inline, but the trancendental functions are done by a call to a function. The speed is nice. I measured a Savage test time of 0.1597 sec. Most libraries of the compilers take on the 68000 (if they are very fast) in double precision more than 30 sec. The chip can do 600000 80 bit multiplications per second. This means that finally it is possible to do some serious calculations at home. Now something about the price. There is a price range for which this computer seems to be a good buy. This would be the range around 8000 dutch guilders (or less of course). In Holland a SUN with proper disks etc would cost close to 15000 and an Apollo DN2500 with disk would be more than 10000 after discount. Actually the DN2500 is slower. It runs on 20 Mhz. The DN3500 from which I type this in runs on 25 Mhz and runs the same program as tested above in 56 sec with code that was produced for the 68020/68030 and its disks are faster. In addition the 56 sec are CPU time. If on the other the machine starts costing more than 10000 guilders it may be too expensive to be attractive. The official price is actually slightly above 10000 guilders, so there may be a problem there. For reference: A fully equipped Mac II cx etc costs here after discount also about 15000 guilders. I have also seen an ethernet card for the Mega and there will be one shortly for the TT too. Atari is mainly waiting on this TT version of the card before they come out with it. It seems the better policy. The price would be very reasonable. Talking about policy: First Atari talks much about new products that never make it to the market or if they make it have generated such an expectations that the actual product is disappointing or too late or whatever. Then we hardly hear anything from them for nearly two years and everyone thinks the ST is their last good product. Then the TT comes out, showing that they can still do something. I believe this last mode of operation wasn't entirely ideal either, because they must have lost the faith of many people. Somehow it seems to me that the proper policy should be inbetween. This could be expressed by a better (software) policy. Many developers have felt in the past that Atari left them out in the cold. Of course Atari isn't a social institute, but somehow I have a feeling that this could be beneficial to both sides. One such act could be to see what is needed to get Simon Poole to make uniterm run on the TT. This program alone made Atari sell many ST computers in Germany and in Holland. Jos Vermaseren Disclaimer: I my employer would have a faster computer he could reject my opinions much faster.