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Received: by minnie.vk1xwt.ampr.org with NNTP id AA5742 ; Fri, 01 Jan 93 01:54:28 EST Xref: sserve comp.unix.bsd:9476 comp.os.linux:20908 comp.unix.pc-clone.32bit:852 Newsgroups: comp.unix.bsd,comp.os.linux,comp.unix.pc-clone.32bit Path: sserve!manuel.anu.edu.au!munnari.oz.au!uunet!math.fu-berlin.de!informatik.tu-muenchen.de!roell From: roell@informatik.tu-muenchen.de (Thomas Roell) Subject: Re: ET4000/W32 and VESA VL-Bus In-Reply-To: hasty@netcom.com's message of 29 Dec 92 22:42:41 GMT References: <1992Dec28.190316.22747@Informatik.TU-Muenchen.DE> <1992Dec28.223727.3569@netcom.com> <1992Dec29.191833.1401@Informatik.TU-Muenchen.DE> <1992Dec29.224241.21987@netcom.com> Sender: news@Informatik.TU-Muenchen.DE (USENET Newssystem) Organization: Inst. fuer Informatik, Technische Univ. Muenchen, Germany Date: Wed, 30 Dec 1992 09:56:45 GMT Message-ID: <1992Dec30.095645.29100@Informatik.TU-Muenchen.DE> Lines: 72 >They do a good DRAM design according to S3 they simulate a VRAM in the >8c801/8c805 design. I don't know the specifics of their design and I doubt >that they are going to make it public. I assume that they simply read the video data for one complete scanline (1024 or 2048 bytes) within one page cycle (tRAS = 90ns, tCAS= 30ns, but just guesses, please could someone look the exact thing up in the databook), which means with a 1024 bytes buffer they would have around 77.6 MB/sec available (with tRAS = 120ns & tCAS = 40ns, this would be 44.3 MB/sec) at 70Hz refresh rate and 1024x768. This might be actually over the limit the graphics engine could make use of. The big BUT is still, how are things looking at 1280x1024, and how are they compared to the 928 which has fully 100MB/sec available ? >>Will be intresting. Have another benchmark number for people who like >>really hot boards ... This is the Nth Engine/250, a VRAM based board >>with a 82C481 on it... Maybe the 928 will be faster ;-) > >My expectation is that is going be faster than 120k xstones :-) Hmmm .... I make no guesses here, but going that high, you'll hit some other limits, which are generally called io-bus limits. On the Nth Engine/250 I computed a xstones rating based upon earlier tests I ran on other 481 boards and the measured rect500 / scroll500 throughput. I expected 128k. The reason why this was not reached was that in some operations, the host to 481 communitcation was simply the limit. Since most commands go exclusively over io-ports (which are slower than memory accesses, and awfully slow on the ISA bus), you can do only around 1 million read/writes per second. For some other operations clipping again got a cpu performance issue. The local bus seems to have solved some things regarding this io-problem, but some other problems will still prevent you from getting the top results by just simply linearly interpolate the xbench results based upon the maximum graphics chip throuput. >Who is the chip manufacturer for the 82c481 and do you have the phone number >for the board manufacturer of the "Nth Engine/250"? The 82C481 is from Chips & Technologies (I thought Amanicio would be the ultimate expert on these things ;-)). The Nth Engine/250 is of course from Nth. Don't have their number here. This board is way out a reach for most people since it is a 2MB VRAM solution with a Bt485 RAMDAC on it. I think it sells for over $1500 ... Anyway I see the prices dropping if 928 boards with 2MB VRAM will actually sell (my personal favourite 928 board is still the ELSA WINNER 1000, which does 1280x1024 non-interlaced for DM 950 in Germany which is about $600). >and at 1024x768. I can't because I am stuck with a low resolution monitor. You can run these higher refresh rates as well. Nobody said that you have to watch xbench running. Just run XS3 and xbench, but without monitor. The results will be correct. >All I want to say is that at $199 the Actix GraphicEngine32 DRAM card is not >a bad card at all. Also, as much as I want to get my hands on a 928 it was >delayed two months and I still have to get hold of one to see how it works. >have the databook and I am all set to got at it. You are right with the point that a 801/805 is right now generally a better buy than a 911/924 buy. And since unluckly the 928 boards seem not to be selling within 2 or 3 months from now they still will be for some time. But if someone can wait this long, he/she will get a better buy with the 928, which also will do 1280x1024 and 1024x768x16bpp and 800x600x32bpp. I predict that this will be much more attractive for people that do not exchange their cards every other week. - Thomas -- ------------------------------------------------------------------------------- Das Reh springt hoch, e-mail: roell@sgcs.com das Reh springt weit, #include <sys/pizza.h> was soll es tun, es hat ja Zeit ...