CPU Compatibility Of BIOS A03

very limited, ngl, 

Given that the current version of most bios is A33 (at least for T7910), why is keeping A03 important?  Granted, I don't know what model computer you have, and A03 may be the latest for your computer.  But it's very easy to determine the latest BIOS and upgrade.  Don't feel limited to A03.

There's a site that gives you some ideas about CPU upgrades.  Try this:

https://www.cpu-upgrade.com/CPUs/Intel/Xeon/E5-1607_v2.html

It does look like there are some options.  Make sure that the new chip is not too "hot", that is, make sure that the new chips thermal design power (TDP) is not too much higher than the 130W of your current chip.

The options seem all to be in the "V2" version level, but a E5-2697 v2, for about $120, might bump your speed a bit. Memory may also be limiting: if you have DDR3-800 installed, moving to DDR3-1600 would probably allow your new CPU to show more power.

Having said all this, you are looking at technology that's 8 or so years old, and any hardware, memory, mobo, or other components may be a bit work-worn.  So there's a risk that you get everything working spiffy, but than something conks out and you end up spending more on upgrading than you would if you found a new machine.  I see a refurbed T3600 with a 2690 (about 3x faster than your machine) with 32Gb of memory - for less than 300 bucks

What model Precision do you have?

It's typically wise to update BIOS before updating hardware.