You don't need to run all . You run A19 update: system will told you what previous version do before. Download A06, A09, A12 and A19. And run them in the order.  
Hi, everyone. I hope I am posting in the correct place. I bought a 2xT5600 a couple of years ago. The one I am asking the following question for is currently on bios version A04. I know, I have been very lazy. But the time as come to upgrade the 2 CPUs in it, and upgrade to a SSD. I also have issues on this machine in that I can only use SATA 0, even though I have done all intel chipset preceedures that have worked on my other machine and the 2 I have previously owned. Anyway, is it OK to update the bios, via flash usb, from v04 straight to the latest v19? Or do I need to do earlier ones first? I think it does not matter, but before I brick my PC I thought it better to ask; I have never made such a huge jump in bios versions before. Thanks
T5600 Bios Update...A04 to A19