SQL Database vs Hyper-V


In the company I work for, we have a slowness problem in the SQL Server 2014 database. Today came a "dba" here to "solve" the problem, according to him the problem of slowness is due to the fact of using Hyper-V , And his solution would be to migrate to VSphere where we would have a 400% performance gain over Hyper-V or even a physical machine.
Is that correct, what did he say?

Its a big claim!

It surprises me how often people throw Bigger Hardware at performance problems, rather than optimising the code. Optimisation of the code will provide much greater scalability than hardware upgrades - and for the lifetime of the application too.

But that's not to say that optimisation is the problem in your case - its just the first place I would look.

I would look at indexing, statistics and of course the SQL being executed. Typically the bottleneck is disk I/O from a hardware perspective. Hyper-V configuration can slow things down if misconfigured. Virtualization configured correctly adds less than 5% overhead. I doubt IBM's solution is 400% faster than MS's.