alt Hacker NewsWhat's the main blocker (other than the current inflated cost) for using HBM instead of DRAM as the primary memory for consumer electronics?
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>> What's the main blocker (other than the current inflated cost) for using HBM instead of DRAM as the primary memory for consumer electronics?
HBM is meant to be integrated into the same package as the CPU, so no more DIMM sockets. It also has higher latency apparently.
I think people might prefer the lower idle power consumption from lpddr over the better bandwidth in hbm in battery powered stuff. That said right now the price is definitely preventing us from finding out.
Why would you want/need to?
The advantage of HBM over regular non-stacked DRAM is memory bandwidth, which also requires a super-wide memory bus - 2048 bits wide for HBM4. Compare that to the 128 bit wide bus of a modern CPU.
So to take advantage of it on the desktop, or anywhere else, you need that 2048 bit wide bus, and a processor capable of consuming 2-3 TB of data per second!
These are not normal requirements, other than for a GPU.
Mainly bus width. Afaik HBM is like 1024 bits vs DDRs 64 so you need lots of transfers in parallel to saturate the bus, and CPUs kinda want 64 bytes of data as that's the size of a cache line ASAP. So you need a ton of in flight transfers which isn't a thing CPUs provide, maybe multicore workloads.
Buy the way you win with CPUs is with latency, and not bandwidth, which is why Apple M series actually uses DDR with lower latency because of the stacking.
In one sense, nothing, in another, everything. It is DRAM, but the bandwidth requirements mean it’s paired to a processor, i.e. no DIMMs. Not 100% sure but things like MacBooks and the Framework tower, where you have fixed RAM for the device lifetime, have ~0 tradeoff.
HBM is a stack of DRAMs, so there is no “instead”.
Nothing except CPU manufacturer choices. Mac laptops use it and they're consumer products.
People will have to get used to buying a fixed amount of RAM with their CPU but thats unlikely to be a problem.
It's not that there's a blocker. It's that it takes roughly 3x the manufacturing capacity to produce an HBM package at the same storage capacity as DRAM. We are sacrificing total bytes for bandwidth.