Being a memory intensive hash, I was wondering if SSD's offer any appreciable performance boost for brute force attacks.
You can speed it up, but not with an SSD or a hard drive.
The fastest calculations today are done with video cards and GPU programming. So if you get a cheap video card and run Cuda or OpenCL you can get quite a lot of performance.
That being said GPU processing vs regular processing have similar limitations when using
scrypt because the most efficient way to perform hashes with ROMmix (part of scrypt) is to cache all of the previously-computed values which requires quite a lot of RAM. GPUs are used for Bitcoin mining.
Installing more memory should increase the speed depending on the operating system and the interaction with the hardware layer (is it a restricted vm, etc). From Wikipedia on CAS Latency.
In asynchronous DRAM, the interval is specified in nanoseconds. In synchronous DRAM, the interval is specified in clock cycles. Because the latency is dependent upon a number of clock ticks instead of an arbitrary time, the actual time for an SDRAM module to respond to a CAS event might vary between uses of the same module if the clock rate differs.
SSDs by contrast
Installing an SSD (and even striping it) will improve performance over a hard drive in terms of virtual memory paging, but will have nowhere near the speed of physical RAM. SSD speeds are usually measured in MB/s and IOPS. Also the SSD is potentially limited by the speed of the controller. There are SSDs that are built onto cards with higher performance controllers bypassing the limits of SATA connections, but even these have speeds around 1000MB/s.
Here's a good place to compare the different speeds. A 500MB/s SSD is .5 bytes/nanosecond.
A nanosecond is 1.0e-9 seconds.
A typical 1-byte compare instruction between memory regions takes 1 cycle.
CPU speed these days is measured in GHz which is 1 billion cycles per second.
I'm not going to compare hard drives.
Nope because you run it in memory not from the hard drive.
The only form of hash cracking I know so far which uses a hard drive, are table lookups like Rainbowtables. Even in that case the benefit of an SSD is limited since it's read in sequentially. SSDs are good for random reads and writes.