If you think it's hard to gain physical access to a consumer desktop, you're out of touch. Most desktops aren't locked inside a datacenter. Memory encryption is a valuable desktop (and laptop) security feature.
When they were the underdog to Intel, they gave away lots of premium features to beat Intel.
Since they got more popular, AMD has been taking away features, or not upgrading old tech, from their desktop/gaming CPUs: Their DDR5 interface is gimped, being slower than Intel now, and still limited to dual channel. Their chipset link is still PCIe 4x4 the same as two generations ago.
If you want these features now, you need a server product.
I don’t even think its exposed in most BIOS’s
I wonder if this was also something they just accidentally broke, or if it was an incompetent attempt at larger segmentation.
AMD Adrenalin, their software that manages things video/GPU features like clip saving, performance settings, game optimizations, update monitoring, performance overlaying, etc - is so fucking bad that if your mouse is set to a refresh rate over 500hz, it is virtually unusable because the mouse cursor takes half a second to respond to inputs. This is running on a card one step down from the flagship, current generation.
Don't even get me started about ROCm on Windows.
Their statement suggests it was a calculated decision, reversed after public backlash. I greatly appreciate they listened to user feedback, but they shouldn't have done it secretly to begin with.
> Based on valuable community feedback, we will reinstate this option in an upcoming BIOS release in July.
1. No dma, instead you use bounce buffers and the cpu manually encrypts and decrypts on behalf of the pcie
2. The IOMMU sets certain pages as unencrypted and ensures the pcie only accesses those pages and that part of ram alone is now not encrypted.
3. Newer pcie devices use the TDISP(handshake) and IDE(aes gcm hardware module related stuff) protocols to do encrypted communication with the CPUs PCIe root hub, where this functionality is called TIO i.e trusted io on amd and TX connect on intel. As far as nvidia GPUs go which is where I have used this, H100 onwards have the feature. Only server xeons and turins etc support this feature on the cpu side. I think some server SSDs do too. Here you get full encryption full DMA at full bandwidth.
AMD silently removes memory encryption from consumer Ryzen CPUs