I’m not sure if this is misleading at all. If anything, they should have mentioned compared to ZRAM. Title is incomplete, but I don’t think it is intentionally misleading here. It just looks like they expect the reader to know CRAM is a replacement for ZRAM. The new compression method CRAM with over 400x speedup is compared to ZRAM method:

A new compression model, called CRAM, offers a different path to compression that avoids swap entirely by keeping the compressed data in memory, and it offers up to 452x the performance of ZRAM.

Because CRAM is stored in RAM and treated as RAM, with full cacheline/byte access, it can be accessed in a read-only fashion with little delay; just the cost of hardware-offloaded compression. As a result, CRAM “runs at DRAM speed,” as the creator says in the slide above. While the graph already looks impressive, it’s a logarithmic scale; CRAM, in the worst case, is doing 489 million operations per second versus ZRAM’s 1.1 million. It’s barely comparable.

Even when you enable writes, CRAM is still much faster than ZRAM; 5.4x in the worst tested case of 20% writes. That’s a huge drop from the 452x read-only case, but keep your context; a 5.4x speedup is still titanic.

Is writes enabled CRAM / ZRAM common? If so, then the post title is definitely misleading.