GDDR7x doesn't come in dimm factor?
In general soldered ram seems to get much higher bandwidth than removeable ram. See ryzen AI Max vs 9950x max ram throughputfor example
GDDR7x doesn't come in dimm factor?
In general soldered ram seems to get much higher bandwidth than removeable ram. See ryzen AI Max vs 9950x max ram throughputfor example
Strix Halo uses a 256bit memory interface, the normal desktop processors only have a 128bit interface, that's the biggest difference in bandwidth. For more bandwidth you need to go to a Threadripper.
Strix Halo seems to use LPDDR with 8000 MT/s, which is a bit faster than the usual 5600 MT/s-6400 MT/s "normal" DDR5-DIMMs (Albeit (expensive) faster ones seem to exist), so there's a slight edge towards soldered memory (not sure about LPCAMM2 and similar tech).
GDDR7 is a different league, a 5070 Ti also has a 256bit memory interface, but has 896GB/s bandwidth, compared to strix halo with 256GB/s
It's really hard to push DDR5 past 6000MT/s on 4+ DIMMs it seems.
I had to get everything top spec to fit 4 channels of 6000MT/s on my 9950x (asus proArt motherboard and the top tier trident neo RAM sticks) -- otherwise it's reportedly unstable.
9950X is dual channel, running 4 DIMMs runs them interleaved, with two DIMMs sharing one physical connection, impacting signal integrity severely. AFAIK this has gotten worse with DDR5 to the point that it's generally recommended to avoid 4 DIMMs unless you really can't get enough RAM otherwise. For maximum bandwidth you need to avoid interleaving.
Strix Halo simply has more memory controllers. Threadrippers are also quad channel, and should be able to run 4 DIMMs at rated speeds, but the cheapest Zen 5 Threadripper seems to be almost double the price of a 9950X3D.
And I presume that doubled price is before you look at the workstation class motherboards, which also tend to be much more expensive.
Thanks for the info on the hardware quirks, useful to know!
We seem to be arriving at a cambrian explosion of viable hardware these days between ARM and x86, soldered vs DIMM, etc.
It's refreshing coming from 20 years of x86 being all that matters.
No.
All GDDR memory is intended only for being soldered around a GPU chip, on the same PCB. This is how they achieve a memory throughput that is 4 to 8 times higher than the DDR memories used in DIMMs or SODIMMs.
We are talking here about slower ram to augment.