If that's on the Blackmagic disk speed test, and you have a Hitachi drive, those speeds are probably valid. Check the SATA entry under Hardware in System Information. If it shows the negotiated link speed as 1.5Gb/s, there's the answer. That equates to 187.5MB.s flat out max, so with a 5400 RPM 2.5" drive you're probably lucky to even see half that. I can't remember my original HDD's speed, but it was significantly slower than 100MB/s.
If you can go from 50MB/s to 250MB/s or faster with an SSD, your MBP will seem like a new machine.
One thing, be careful with your letter case when dealing with size and speed abbreviations. M means mega, or million, and m means milli, as in 1/1000th. Also, B means bytes and b means bits. It can be confusing to readers, depending on context, especially between MB and Mb. The former is eight times larger.
