Yes, another Gigabyte board. It isn't often that I recommend two products from the same manufacturer at once, but I feel this is a special case. At $299, the price of the GA-EX58-UD5 is more mid-range for EX58 motherboards. As such, it has many competitors. But it seems that none of them provided the same combination of expected reliability and features that can be found in this Gigabyte board.
Compared to the cheaper GA-EX58-UD3R, the UD5 features more RAM slots. The maximum amount of RAM supported - 24GB - is exceptional. ASUS offers a board (the P6T Deluxe) with a similar price and feature set, but it only accepts 12GB of RAM. This board also offers three-way SLI for both ATI and Nvidia products. The UD5 also seems to perform well when compared to similarly priced boards, like the Asus P6T Deluxe and the MSI X58 Eclipse. Motherboard performance doesn't make or break most PCs, but this board does have an edge.
There are some down-sides to the Gigabyte GA-EX58-UD5, the most notable of which is power consumption. Tests seem to indicate that this board uses more power at both Idle and at Load than any other X58 board on the market. However, the difference is relatively small, on the order of a few percent. This could be a major flaw when speaking of a motherboard meant for low-end systems, but if you're buying a Core i7, performance and features are probably more important.
ASUS has always made high-quality boards, and in this case, I've picked the best of the best. The ASUS P6T6 WS Revolution is not a budget board. It is a motherboard aimed at people wanting tons of features and at gamers wanting high-end performance in the most demanding games. Its price tag of $359 dollars reflects this, but you get what you pay for.
Probably the most interesting feature of the P6T6 WS Revolution is the "True @16 3-Way SLI" feature which ASUS includes in this motherboard. This motherboard has been set up for the possibility of three-way GPU setups. Its three PCIe primary slots are spaced to fit three double wide cards. Whats more, this board also runs all three cards at full x16 speed. That is impressive, considering that most Core 2 Duo motherboards are forced to run only two cards at x8 lane speeds. PCI-E lanes and speed are explained here. Oh, and this ASUS board can also run 3-way Crossfire at the same blazing fast speed.
The P6T6 WS Revolution gets rid of most older technology. IDE, Floppy, and old-fashioned PCI do not exist on this board. This could be a problem if you have some old components you can't part with, but it does help result in a board layout that is not cluttered, despite a wealth of features. The only real downside to this board is its limited RAM capacity. 12GB isn't much for a motherboard of this price. Even the $199 dollar Gigabyte board can support more. However, 12GB will likely be more than enough unless you're planning to build an extremely high-end workstation. So, with that catch stated, it is safe to say the P6T6 WS Revolution is the best high-end X58 motherboard you can buy.