Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: "Chris M. Thomasson" Newsgroups: comp.arch Subject: Re: Is Intel exceptionally unsuccessful as an architecture designer? Date: Sat, 21 Sep 2024 13:24:52 -0700 Organization: A noiseless patient Spider Lines: 119 Message-ID: References: <2935676af968e40e7cad204d40cafdcf@www.novabbs.org> <21028ed32d20f0eea9a754fafdb64e45@www.novabbs.org> <20240918190027.00003e4e@yahoo.com> <920c561c4e39e91d3730b6aab103459b@www.novabbs.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 21 Sep 2024 22:24:53 +0200 (CEST) Injection-Info: dont-email.me; posting-host="9fabd7f027d8f87c91e752d958126e44"; logging-data="1824525"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19Zhl+jQuPbRuL2iygeeY4SraNEIanTnho=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:iaQwrE3d6Xz0X3sJOWstWvZZz+o= Content-Language: en-US In-Reply-To: Bytes: 5692 On 9/21/2024 9:39 AM, Brett wrote: > Chris M. Thomasson wrote: >> On 9/20/2024 6:48 PM, MitchAlsup1 wrote: >>> On Sat, 21 Sep 2024 1:12:38 +0000, Brett wrote: >>> >>>> MitchAlsup1 wrote: >>>>> On Fri, 20 Sep 2024 21:54:36 +0000, Chris M. Thomasson wrote: >>>>> >>>>>> On 9/20/2024 2:32 PM, Lawrence D'Oliveiro wrote: >>>>>>> On Fri, 20 Sep 2024 11:21:52 -0400, Stefan Monnier wrote: >>>>>>> >>>>>>>>> The basic issue is: >>>>>>>>> * CPU+motherboard RAM -- usually upgradeable >>>>>>>>> * Addon coprocessor RAM -- usually not upgradeable >>>>>>>> >>>>>>>> Maybe the RAM of the "addon coprocessor" is not upgradeable, but the >>>>>>>> addon board itself can be replaced with another one (one with more >>>>>>>> RAM). >>>>>>> >>>>>>> Yes, but that’s a lot more expensive. >>>>>> >>>>>> I had this crazy idea of putting cpus right on the ram. So, if you add >>>>>> more memory to your system you automatically get more cpu's... Think >>>>>> NUMA for a moment... ;^) >>>>> >>>>> Can software use the extra CPUs ? >>>>> >>>>> Also note: DRAMs are made on P-Channel process (leakage) with only a few >>>>> layer of metal while CPUs are based on a N-Channel process (speed) with >>>>> many layers of metal. >>>> >>>> Didn’t you work on the MC68000 which had one layer of metal? >>> >>> Yes, but it was the 68020 and had polysilicide which we used as >>> a second layer of metal. >>> >>> Mc88100 had 2 layers of metal and silicide. >>> >>> The number of metal layers went about:: >>> 1978: 1 >>> 1980: 1+silicide >>> 1982: 2+silicide >>> 1988: 3+silicide >>> 1990: 4+silicide >>> 1995: 6 >>> .. >>> >>>> This could be fine if you are going for the AI market of slow AI cpu >>>> with huge memory and bandwidth. >>>> >>>> The AI market is bigger than the general server market as seen in >>>> NVidea’s sales. >>>> >>>>> Bus interconnects are not setup to take a CPU cache miss from one >>>>> DRAM to a different DRAM on behalf of its contained CPU(s). >>>>> {Chicken and egg problem} >>> >>> Thus a problem with the CPU on DRAM approach. >> >> It would be HIGHLY local wrt its processing units and its memory for >> they would all be one. >> >> The programming for it would not be all that easy... It would be like a >> NUMA where a program can divide itself up and run parts of itself on >> each slot (aka memory-cpu hybrid unit card if you will). If a program >> can be embarrassingly parallel, well that would be great! The Cell >> processors comes to mind. But it failed. Shit. > > Cell was in the PlayStation which Sony sold a huge number of and made > billions of dollars, so successful, not failed. Touche! :^) However, iirc, not all the games for it even used the SPE's. Instead they used the PPC. I guess that might have been due to the "complexity" of the programming? Not sure. > I programmed for Cell, it was actually a nice architecture for what it did. Iirc, you had to use DMA to communicate with the SPE's? > If you think programming for AI is easy, I have news for you… > > Those NVidia AI chips are at the brain damaged level for programming. No shit? I was thinking along the lines of compute shaders in the GPU? > 10’s of billions of dollars are invested in this market. > >> A system with a mother board that has slots for several GPUS (think >> crossfire) and slots for memory+CPU units. The kicker is that adding >> more memory gives you more cpus... >> >> How crazy is this? Well, on a scale from: >> >> Retarded to Moronic? >> >> Pretty bad? Shit... >> >> Shit man, remember all of the slots in the old Apple IIgs's? >> >> ;^o >> >> >>> >>>> Such a dram would be on the PCIE busses, and the main CPU’s would barely >>>> touch that ram, and the AI only searches locally. >>> >>> Better make it PCIe+CXL so the downstream CPU is cache coherent. >> >> > > >