6 ms·
How much relevance does JEDEC still have? I would think NVIDIA in particular and other chip makers/integrators like apple make up their own standards now. It
by paddy_m 3y ago
How much relevance does JEDEC still have?
I would think NVIDIA in particular and other chip makers/integrators like apple make up their own standards now. It also seems less relevant because memory is rarely interchangeable anymore
- sliken 3y agoDo you have any evidence that Nvidia or Apple are using non-standard memory chips? Link? From what I can tell they are both using standard chips, but very wide memory interfaces. Apple's lowest end is 128 bit, but offer 256, 512, and 1024 bit wide memory interfaces for more bandwidth, which is mostly a benefit for the iGPU in all of Apple's m series CPUs. This is part of why Apple are pretty good at LLMs, especially those needing more ram than is in even the most expensive GPUs. Sad that the vast majority of x86-64 laptops and desktops have the same bus width of decades ago, while the core counts are ever increasing.
- jsheard 3y agoNvidia and Micron came up with GDDR6X, which isn't a JEDEC standard. JEDEC did standardize GDDR5X before that, but only Micron ever made it and only Nvidia ever used it AFAIK.
- zeusk 3y agoJEDEC never "standardized" GDDR6x that Nvidia does use; Micron and Nvidia worked closely on both GDDR6x and GDDR5x
- kllrnohj 3y ago> Apple's lowest end is 128 bit, but offer 256, 512, and 1024 bit wide memory interfaces for more bandwidth Apple doesn't have any 1024-bit offerings. The Ultras are 2x 512-bit which is different from a true 1024-bit since it's a NUMA configuration (two different memory controllers). > Sad that the vast majority of x86-64 laptops and desktops have the same bus width of decades ago, while the core counts are ever increasing. The consistent trend is CPU performance on consumer workloads is still much more sensitive to memory latency than it is bandwidth. This is probably also why those 512-bit M1/2 Max's don't even bother to let the CPU make use of it, they top out at "just" 200GB/s memory bandwidth even though there's 400GB/s available to the SoC as a whole. Being able to pair a lot of DRAM with the GPU of an M* Max/Ultra is definitely a currently unique perk, but the bandwidth numbers available to those GPUs are not actually all that special. Desktop GPUs passed 400GB/s mark way back in 2016, and are currently pushing 1TB/s in modern flagship offerings.
- sliken 3y agoAgreed. I did see a limit of 220GB or so for the M2 max, but haven't seen an updated number for the M3 max. Certainly GPUs have great bandwidth, but get quite expensive if you need more than 24GB ram. I've been impressed how well the M3 max runs 70B or larger models, plenty for single user use anyways.
- hedgehog 3y agoApple and NVIDIA are both members of JEDEC...
- monocasa 3y agoHBM is a JEDEC spec these days. Apple's on package memory is still LPDDR.
- deleted 3y ago[deleted]
- ajross 3y agoJEDEC isn't a memory technology monopoly or anything, they're just a standards organization. You have a situation where lots of companies need to make products that interoperate, but interoperation is complicated in electrical engineering. There are a *lot* of ways to get a memory interconnect wrong. So the solution is to pick (or create) a separate, notionally independent body staffed and supported by representatives of all the relevant stakeholders, and have them write "standards" that everyone agrees to adhere to. The body doesn't invent the technology, that happens at the individual chip companies. They then present their proposals to JEDEC[1] and everyone argues and agrees on what will go into GDDR19 or whatnot. And JEDEC then publishes the standards for all to see. [1] Or whoever, JEDEC does DRAM, but there's a USB Consortium, Bluetooth SIG, WiFi is under IEEE, etc...
- pillusmany 3y agoStandardized memory chips allows economy of scale to work.
- Dalewyn 3y ago>How much relevance does JEDEC still have? Ah, a FOSSy dev insistent that his bits are gibi- and mebi- and kibi-bytes.
- ryukoposting 3y agoThe physical memory modules might not be interchangeable, but JEDEC is still extremely important to hardware and firmware engineers. It gives us a baseline - we know anything that says "JEDEC" will play nice with our SoC's QSPI/DDR peripherals.
- paulmd 3y agoNVIDIA has basically been doing that with GDDR5X and GDDR6X already - they are "official standards" but nobody besides NVIDIA actually uses them.