Valve announced its ambitious new portable PC platform, the Steam Deck, last week, with three distinct models with varying technical specifications to choose from. One facet of all three that was standard, however, was the amount of RAM each one will ship with, which now seems a lot better than initially suspected.
In the original technical specifications, Valve noted that the 16GB of LPDDR5 memory was running in dual-channel, with an expected bandwidth of 5,500 MT/s. The latter figure is still correct, but Valve has updated the official product page to reflect that the memory is, in fact, quad-channel, not dual, offering up a lot more bandwidth to the APU powering the device.
This confirms what some had already suspected when first presented with the technical specifications, given that the expected bandwidth relative to the APU powering the Steam Deck didn’t seem to add up.
A discussion and curiosity is resolved now.Van Gogh, which is used by Valve’s Steam Deck, has 4 UMCs.I expected 4x 16-Bit (a memory channel under LPDDR5 is actually 16-Bit wide). The official spec claimed 5.5 Gbps (dual-channel), which didn’t made sense to me.It got corrected pic.twitter.com/orgzMKJldE
— Locuza (@Locuza_) July 19, 2021
What this means is that the APU will have much more memory bandwidth to utilize, which is very important given its architecture. An APU is a combination of a CPU and GPU on the same silicon, which means that both share the same memory pool. This is different to traditional desktop PCs and laptops, where the CPU has exclusive access to your system’s RAM (usually dual-channel DDR4 memory) while your GPU has its own memory which is generally much faster and contains a much wider bandwidth (most GPUs ship with GDDR6 or GDDR6X memory today).
In the case of the Steam Deck, having more memory bandwidth means better shared allocation between the GPU and CPU, which means better performance when playing games. Not that anything has changed since Valve opened preorders for the Steam Deck, but at least now you can rest assured that you’re getting what is pretty standard for this type of setup.