Maximus V Extreme: Pushing LGA1155 To Its Limits
For you extreme overclockers and 4-way GPU nuts who have been waiting for the Extreme board to arrive: the time is.. very close. Like the Maximus IV Extreme(-Z) last year, the Maximus V Extreme represents ROG team's tailoring to the very high end. How exactly? Read on!
Most cases support wider rather than taller motherboards, so the EATX form factor is be more compatible for existing chassis.
10 SATA is split across the 8 right angled to the side of the board (Z77+ASMedia), one on the base (Z77) and one on the mPCIe Combo card (Z77). There are two sets of (black) USB 2.0 pin-outs for four ports and two (red) USB 3.0 front panel pin-outs too. Nestled into the bottom corner is the BIOS switch, and above it the SubZero Sense K-type connector.
4-way SLI/CrossFire-X & PCI-Express 3.0
4-way SLI/CrossFire-X and all the CPU power you can muster has been a staple diet of performance enthusiasts for as long as... well, 4-way GPU has been available. Where the Maximus V Formula serves up a 3-way GPU game-o-thon, the Maximus V Exterme ups the ante with full 4-way support supplied over its four, red, PCI-Express 3.0 slots shown above.
That part is easy, however it's how they are connected that makes the Extreme different.
As the LGA1155 CPUs have only one PCI-Express 16x slot for graphics, this is connected to a hidden PLX PCI-Express 3.0 multiplier nestled under the central ROG heatsink, taking its place between CPU socket above and the PCIe slots it connects to beneath. The PLX chip multiples the single 16x by two, so that extreme gamers and benchmarkers are served up 8x bandwidth across all four PCIe slots. However, adding an extra chip also adds a data hop, which means a bit of additional latency. While necessary for 4-way users, 2-way benchmarkers (normal gamers won't notice) don't want the drop in scores. It's a similar situation that was firstly highlighted on older motherboards with the NF200 chip. In light of this, ROG engineers took the time to device a custom system of PCI-Express lane switching where if only one or two graphics cards are installed then the PCI-Express 3.0 lanes are reassigned to connect directly to the CPU, bypassing the PLX chip altogether and completely minimizing the latency.
Intel Thunderbolt & the Rear I/O layout
Just like the P8Z77-V Premium that recently launched, the Maximus V Extreme adds an Intel Thunderbolt port to its hardware lineup at the very top of the rear I/O.
The mPCIe Combo card familiar on all Maximus V boards (but vacant in the picture above sorry) is placed next to it. Like the Formula this comes with an 802.11n WiFi card bundled in the mPCIe slot, with the mSATA slot on the opposite side free to upgrade.
Next are two buttons representing the ever useful BIOS Flashback at the bottom and Clear CMOS at the top. Next to these are four USB 2.0 ports, with the bottom white slot doubles up as the BIOS Flashback socket, but can be used as a normal USB port in Windows. Four USB 3.0 ports (in blue), Intel Gigabit LAN, DisplayPort and HDMI video outputs, optical S/PDIF and 7.1 channel HD surround sound. The PS2 keyboard/mouse port is still there because extreme overclockers can prefer to turn off the USB entirely, working entirely through the legacy I/O chip that is unaffected by extreme changes to frequencies across the board. Let's not forget the gamers too - mechanical keyboards are bringing back the PS2 connector as it can accept more simultaneous key presses.
OC Key, VGA Hotwire & Subzero Sense
Remember the OC Key from the Rampage IV Extreme? That comes bundled in the Maximus V Extreme box. In fact, the entire set of OC Key, VGA Hotwire and Subzero Sense is added to its feature set.
Up in the top right there's also the debug LED, slow mode switch for extreme OCers, ProbeIt readouts, the Go Button for on the fly OC Profile switching, and four VGA Hotwire 3-pinouts.
The new ROG MATRIX HD 7970 and recently released GeForce GTX 680 DirectCU II both have VGA Hotwire ports on them that sync-up with both these Extreme boards.
