Re: reiserfs performance on ssd

[PFC <lists@peufeu.com>]

	While I like the idea, the iram implementation is horrible for various  
reasons :

	- no ECC
	- It uses SATA hence only a very little part of the RAM speed is used,  
and large latencies are introduced.
	- I wouldn't trust it for critical data.

	Then, it would be faster to just add the RAM on the motherboard and  
create a ramdisk...

	Also : THE PCI BUS MUST DIE !

	It's no wonder reiserfs is slower on this thing ; reiserfs is optimized  
for hard disks which have high seek latencies.
	For RAM storage, things like hash tables are a lot better than trees,  
because you don't care about sequential scanning and locality of  
reference... (as long as the items are a bit larger than a cache line,  
which is obviously the case here).
	A filesystem that pauses and thinks for 0.5 ms of CPU time to avoid a 5  
ms HDD seek time is a good thing, but for SSD storage you want a FS that  
doesn't think at all.
	Using ReiserFS on this is like hitting a nail with a screwdriver.

	Try tmpfs, I'm curious about the results.

	Crazy idea :
	- Ask the motherboard manufacturer to stick a battery on the mobo so that  
the contents of RAM survive reboot
	- Tweak the BIOS so that RAM isn't cleared at boot
	- Teach the Kernel to be cautious while booting and not overwrite the  
previous RAMDISK
	- You have persistent ramdisk. Stick your reiserfs journal on it, enjoy.