The testing data presented in the last several articles shows that there are some workloads where bcache works well and many workloads where it doesn’t work well. But remember that bcache is still in early development so I’m not surprised that it doesn’t have good performance in certain areas.(...)So is bcache ready for prime time use? The author of bcache readily admits that it’s not and I agree.
So any good programmer reading this: this is your chance to get involved! ;-) For everyone else, stay tuned, I have a feeling it's going to get there eventually. By then SSDs will hopefully be more affordable, too.