How fast is flash memory?

[GwymWeepa]

So Revolution is supposed to have 512 megs of Flash memory. Any idea whether it will be solely for saves, or perhaps solely for system cache, a bit of both? Just how fast is current flash memory and how does that compare to harddrives?

 

[Guden Oden]

The speed of flash depends on a lot of factors, not least how wide the data bus to the memory is. It's too general a question to be possible to answer straight up, it could be anywhere from a few hundred kilobytes/s to many megabytes/s transfer rate. Access time would be orders of magnitude faster than a harddrive, likely in the a few hundred nanosecond range.

 

[ShootMyMonkey]

Depends on the size as well. The big flash-based hard drive replacements (those that get to 60-80 GB in a 3.5" form factor) tend to have much higher throughput -- up to hard drive level speeds, and slower access times. 0.05-1 millisecond(s). The little key drives tend to be far slower throughput, but very fast access times... anywhere from 1-10 MBytes/sec and access times in the 80-200 ns range, although NOR Flash can have much faster access times as low as 25 ns depending on the conditions.

They also don't tend to get high throughput until you're transferring large streams. If you're sending files that are just a few kilobytes each, they'll probably go slower than 500 KB/sec.