Read and write speed of SanDisk Extreme SSD is slow in Mac Book Pro

I recently installed the SanDisk Extreme SSD in my Mac Book Pro. After installing it, I started copying the data in it, but was sad to find that there was no improvement in the transfer speed of the data in it. I used the black magic benchmarking tool to check the transfer speed only to find that it was as low as 100 mbps. Can someone tell me why this is happening, I mean SSDs are meant to be faster in transfer of data from one side to another? An someone tell me what the problem can be with the SSD?

I’ll suggest that you use some other software other than Black Magic benchmarking. The black magic benchmarking tool uses compressed data to check the transfer rate of the hard disk and not raw data. The transfer speed of SSD won’t be properly recognized by this method. Also the transfer speed depends on the format of the data you are transferring. Not just format, but the transfer rate also depends on the amount of data you are transferring. If you are transferring large number of small files, then chances of low transfer is also possible.

As you mentioned in your question that you are using Mac Book Pro which was released in year 2009. This laptop has Nvidia’s SATA chipset in it which is somewhat incompatible with the SSDs. I think this must be the reason that you are getting the low transfer speed on yurt laptop. At the time of making Mac Book Pro, the developers had never designed it for such high transfer rate for the data. Due to this reason, the SSD cannot give full functionality with your Mac Book Pro and thus you are noticing the underperforming results from the SSD.

You can try aligning the drives of the SSD properly to suit the speed along with the Nvidia SATA chipset. According to what speed you are getting, it seems that by default the SSD has been aligned by the Nvidia SATA chipset on SATA 1 speed. You can try for better alignment. I can’t guarantee you that after alignment will give you full speed that SSD should give, but at least there will be some improvement in the transfer speed.