Why don't they just put ram slots on the card so you can augment the fast ram
Also, we had memory slots on '90s cards. They were extremely expensive and proprietary. Ever saw a Matrox VRAM card? I never did.
PCI is (was) allowed to be even longer. Old AT and ATX cases had a slotted support bracket to hold the far end of the PCI cards. See how an Adaptec 2400A looks like.
Like the M.2 connector?
> Data lines need to be longer
Like the data lines going all the way to an on-motherboard storage device?
Yes, though likely something with a higher pin count since memory access is more likely to be random and can be parallel versus block storage.
> Like the data lines going all the way to an on-motherboard storage device?
Yes. Why would a GPU manufacturer/packager take on that cost, if it’s presently served well enough for most people by offloading it onto other parts of the system?
This is why there are several proposals of improved forms for memory modules, which use different sockets, like LPCAMM2, which should be able to work with faster memories.
However even LPCAMM2 is unlikely to work at the speeds of soldered GDDR7.
Moreover, when you do this manually, unless it is something that you do every day it may be quite difficult to be certain that soldering has been done well enough to remain reliable during long term use. In the industry, very expensive equipment is used to check the quality of soldering, e.g. X-ray machines.
So unlike inserting a memory module in a socket, which is reasonably foolproof, soldering devices is not something that could be used in a product sold to the general population.
When I was young, there still existed computer kits, where you soldered yourself all the ICs on the motherboard, so you could get a computer at a much lower price than for a fully assembled computer. My first PC was of this kind.
However, at that time PCs were still something that was bought by a small fraction of the population, which were people that you could expect to be willing to learn things like how to solder and who would be willing to accept the risk of damaging the product that they have bought. Today PCs are addressed to the general public, so nobody would offer GPU cards that you must solder.
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 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
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.
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.
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.
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.
Not as GPU VRAM expansion.