[cctalk] Re: i860 vs. i960 WAS Intel's i860, Cray-On-A-Chip
fre 2022-09-23 klockan 22:27 -0700 skrev Cameron Kaiser via cctalk: > > I always thought the i960 was an upgrade to the i860 (sort of like > > i386 to i486 upgrade). However, based on the info on wiki it seems > > as if the i960 actually came first and although a RISC chip it was > > in no way in the same league as the i860. Anyone can clarify or > > verify this? > I'm not even sure I'd call them related. The i960 is a very > different, almost > "normal" RISC chip compared to the i860, though it uses Berkeley > register > windows like SPARC. It has excellent XOR performance, so it got used > a lot > later on in RAID arrays (my Apple Network Server 500 has a RAID card > with an > i960 on it). A few systems used it and it was popular in military > applications > but it never achieved its potential mostly due to internal politics > at Intel -- > not because it sucked -- and the DEC StrongARM settlement mostly put > a stake > through it. > and a number of X terminals.
[cctalk] Re: i860 vs. i960 WAS Intel's i860, Cray-On-A-Chip
On Fri, Sep 23, 2022, 21:50 Ali via cctalk wrote: > I always thought the i960 was an upgrade to the i860 (sort of like i386 to > i486 upgrade). However, based on the info on wiki it seems as if the i960 > actually came first and although a RISC chip it was in no way in the same > league as the i860. Anyone can clarify or verify this? They're totally unrelated, except that they both came from Intel. The i960 was the BiiN processor, stripped (in most versions) of the tagged memory and capability architecture. The BiiN processor was an attempt to keep the "good parts" of the iAPX 432, without the huge performance penalty of the 432 as compared to "normal" processors (e.g., MC68000). So the i960 basically threw away the BiiN's vestiges of the 432, transforming it into a "normal" processor. It was successful in embedded applications, such as laser printer. I don't know the development history of the i860, but it is not similar in any way to the i960. There were some Unix workstations based on the i960, but many sources claim that it didn't meet expectations because of the exposed pipeline (making compiler development difficult), imprecise exceptions, and expensive context switching.
[cctalk] Re: i860 vs. i960 WAS Intel's i860, Cray-On-A-Chip
> I'm not even sure I'd call them related. The i960 is a very different, > almost > "normal" RISC chip compared to the i860, though it uses Berkeley > register > windows like SPARC. It has excellent XOR performance, so it got used a > lot > later on in RAID arrays (my Apple Network Server 500 has a RAID card > with an > i960 on it). Thanks that explains most of what I have seen. I have also seen it used on a number of SCSI controllers of yore and I believe the HP LJ 4 also used the i960 for its processor. Outside of the Hauppauge 4860 I don't think I have ever seen a PC architecture board with the i860 and I am not even sure how much use the Hauppauge board got out of the i860 except for video processing. -Ali
[cctalk] Re: i860 vs. i960 WAS Intel's i860, Cray-On-A-Chip
> On Sep 23, 2022, at 11:50 PM, Ali via cctalk wrote: > > I always thought the i960 was an upgrade to the i860 (sort of like i386 to > i486 upgrade). However, based on the info on wiki it seems as if the i960 > actually came first and although a RISC chip it was in no way in the same > league as the i860. Anyone can clarify or verify this? I have very bad memories of the i960 from my time at Chipcom. The main memory I have is that it uses an utterly misdesigned queue based I/O architecture, full of race conditions. I think it's the same "design" used in the much maligned i82586 Ethernet chip. The odd thing is that others had done correct and race-free queue designs a decade or two earlier, but Intel never showed any sign of design competence and it is just an example of this that they screwed up I/O queues so badly. paul
[cctalk] Re: i860 vs. i960 WAS Intel's i860, Cray-On-A-Chip
On Sat, 24 Sept 2022 at 05:50, Ali via cctalk wrote: > > I always thought the i960 was an upgrade to the i860 (sort of like i386 to > i486 upgrade). However, based on the info on wiki it seems as if the i960 > actually came first and although a RISC chip it was in no way in the same > league as the i860. Yes, me too. This has come as a bit of a surprise to me in fact. -- Liam Proven ~ Profile: https://about.me/liamproven Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmail.com Twitter/LinkedIn: lproven ~ Skype: liamproven UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053
[cctalk] Re: i860 vs. i960 WAS Intel's i860, Cray-On-A-Chip
> I always thought the i960 was an upgrade to the i860 (sort of like i386 to > i486 upgrade). However, based on the info on wiki it seems as if the i960 > actually came first and although a RISC chip it was in no way in the same > league as the i860. Anyone can clarify or verify this? I'm not even sure I'd call them related. The i960 is a very different, almost "normal" RISC chip compared to the i860, though it uses Berkeley register windows like SPARC. It has excellent XOR performance, so it got used a lot later on in RAID arrays (my Apple Network Server 500 has a RAID card with an i960 on it). A few systems used it and it was popular in military applications but it never achieved its potential mostly due to internal politics at Intel -- not because it sucked -- and the DEC StrongARM settlement mostly put a stake through it. -- personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckai...@floodgap.com -- The faster we go, the rounder we get. -- The Grateful Dead, on relativity --
