I’m looking at people running Deepseek’s 671B R1 locally using NVME drives at 2 tokens a second. So why not skip the FLASH and give me a 1TB drive using a NVME controller and only DRAM behind it? The ultimate transistor count is lower on the silicon side. It would be slower than typical system memory but the same as any NVME with a DRAM cache. The controller architecture for safe page writes in Flash and the internal boost circuitry for pulsing each page is around the same complexity as the memory management unit and constant refresh of DRAM and it’s power stability requirements. Heck, DDR5 and up is putting power regulation on the system memory already IIRC. Anyone know why this is not a thing or where to get this thing?
Modern flash is already faster than your pci bus, and it’s cheaper than dram. Using ram doesn’t add anything.
It uses to be a thing before modern flash chips, you’d have battery backed dram pci-e cards.
It would improve access latency vs flash though, despite less difference in raw bandwidth
It adds an additional memory controller on a different bus and infinite read/write cycling to load much larger AI models.
Memory connected via the pci bus to the CPU, would be too slow for application use like that.
Apple had to use soldered in ram for their unified memory because the length of the traces on the mobo news to be so tightly controlled. Pci is way too slow comparatively.
Not at all. An NVME already works as I clearly stated in the post. The speed is irrelevant with very large models. They are MoEs so they get loaded and moved around in large blocks once per inference. The only issue is cycling a NVME. They will still work, it would just be nice to not worry about the limited cycle life. I am setting up agentic toolsets where models will get loaded and offloaded a lot. I do this regularly with 40-50GB models already. I want to double or quadruple this amount.
https://www.intel.com/content/www/us/en/content-details/842211/optimizing-system-memory-bandwidth-with-micron-cxl-memory-expansion-modules-on-intel-xeon-6-processors.html
Found via Wendell: YouTube
edit: typo