The m1.xlarge pairs 4 vCPU with 15 GiB of RAM, the 3.75 GiB-per-vCPU ratio that marks a general-purpose instance. In the name, "m" is the general-purpose line, "1" is the generation and "xlarge" is the size within the m1 family. It runs on Intel Xeon Family at 1.8 GHz, and AWS introduced it in October 2007. AWS has since shipped m2, m3, m4 and m5; m2.xlarge is the direct replacement at this size. gp.vs1.large on Rackspace Spot lines up one-for-one: 4 vCPU and 16 GiB, $0.350/hr on AWS in US East (N. Virginia), from $0.011/hr on Rackspace Spot.
Match qualityNo local disk
m1.xlarge comes with 4 × 420 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.
