RWEverything (Read & Write Everything) will allow you to access pretty much all your computer hardware, great for testing system performance and running diagnostics.

You will be able to access PCI (PCI Express), PCI Index/Data, Memory, Memory Index/Data, I/O Space, I/O Index/Data, Super I/O, Clock Generator, DIMM SPD, SMBus Device, CPU MSR Registers, ATA/ATAPI Identify Data, Disk Read Write, ACPI Tables Dump (include AML decode), Embedded Controller, USB Information, SMBIOS Structures, PCI Option ROMs, MP Configuration Table, E820, EDID and Remote Access. And also, a Command Window is provided to access hardware manually.

RWEverything is quite a powerful utility designed along with hardware engineers, firmware (BIOS) engineers, driver developers, QA engineers, performance test engineers, and diagnostic engineers in mind. That being said, it's important to note that this is geared towards experienced users, any modifications made to your hardware settings very well could damage your system if something goes wrong. Use this product at your own risk.

Version History for RWEverything:
http://rweverything.com/changelog/