m1.medium is AWS's general-purpose EC2 size at 1 vCPU and 3.75 GiB. In the name, "m" is the general-purpose line, "1" is the generation and "medium" is the size within the m1 family. It runs on Intel Xeon Family at 1.8 GHz, and AWS introduced it in March 2012. AWS has since shipped m2, m3, m4 and m5; m3.medium is the direct replacement at this size, scoring 22,901 CoreMark/s against this instance's 16,889 — roughly 36% more throughput for the same vCPU count. Rackspace Spot maps this to gp.vs1.medium (2 vCPU, 4 GiB), giving you 1 more vCPU and 0.25 GiB more memory, $0.087/hr on AWS in US East (N. Virginia), from $0.002/hr on Rackspace Spot.
Match qualityNo local disk
m1.medium comes with 1 × 410 GB HDD attached to the machine. Rackspace Spot nodes use network storage only, so that disk does not come with it.
If you were using the local disk as fast scratch space — temporary files, a local cache, an index — you will need a persistent volume or object storage instead, and both are slower to read. If it was just extra space you never depended on, nothing changes.
