More C7X99-OCE Details
The C7X99-OCE’s four x16-length PCIe lanes are hard-wired with x16-x8-x8-x8 pathways, so you’ll never get true x16 mode for three-way SLI. That’s not a worry for us, since we haven’t tested a card yet that needs more than eight lanes of PCIe 3.0 to reach optimal performance. On the other hand, a fixed x8 slot might bother a few purists.
The hard-wired slot arrangement could be a little more troublesome to owners of 28-lane (Core i7-5820K) processors, since the reduced lane count is divided into x16-x0-x8-x0 pathways.
And the documentation couldn’t be less clear. Even after figuring out that engineers numbered these slots from left to right (rackmount orientation) rather than top to bottom (for tower users), apparently conflicting information on the manual and website forced me to test every possible slot configuration with two Radeon R9 290X graphics cards and two processors (Core i7-5960X and -5820K) to confirm that the things I wasn’t seeing weren’t there.
Two additional card slots house PCIe 2.0 x1 interfaces within x4 connectors.
Builders who are able to avoid covering the bottom edge will have access to a row of overclocking buttons, beginning with the baseline “home” button, progressing to the motorcycle-themed OC1 button (rated at 15% O/C), the F1 race car OC2 (rated at 20-25% O/C), a fighter jet-looking OC3 (user-programmable) button and a Memory O/C button. Deploying OC1 gave us 4GHz at 1.4V CPU core and cache, OC2 facilitated 4.3GHz at 1.4V CPU core and cache and Memory O/C triggered our memory’s DDR4-3000 XMP profile. We’ll discuss that on the next page.
Additional buttons include a CLR-CMOS button just above the second x16 slot on the C7X99-OCE’s rear edge and a BIOS Recovery button next to its two-digit status coded display.
You might have noticed that the C7X99-OCE doesn’t have any USB 2.0 front-panel headers, or even rear-panel ports. Lined up along the bottom edge, data headers include only a nine-pin serial port in the back corner, a proprietary interface for Supermicro’s OC Front Panel bay adapter toward the middle, a TPM header, front-panel power/reset/LED connections and USB 3.0. OEM customers can have four of the board’s eight USB 3.0 headers upgraded to USB 3.1 for an added fee.
The front-panel audio connector is found next to I/O panel jacks, easing its implementation with short cables. Some builders might complain that they can’t hide a cable that runs across the motherboard’s surface, but we’ve seen far too many cases with cables that can’t reach the traditional bottom-rear corner location (where Supermicro places the C7X99-OCE’s serial port).
Stripping a motherboard down to its essentials leave little room for error when it comes to component placement. The potentially-problematic front-panel USB 3.0 header is far enough from the third graphics card to allow most long graphics coolers to fit, and all of the SATA headers face forward to avoid conflict with extra-long cards. And while five isn’t a generous number for four-pin fan headers, at least these are spaced properly for two front case fans, a rear case fan and front/rear CPU cooler fans.
Supermicro didn’t include the C7X99-OCE’s installation kit in our package, though a quick look at one of our preferred sellers shows that it includes six SATA cables and a single SLI bridge. Supermicro instead added its OC Front Panel accessory, which duplicates most of the board’s overclocking-centric buttons to a case’s 5.25” bay. This device is not specific to our board, however, as there are no headers on the C7X99-OCE to connect its USB 2.0 port.