Here's a few shots of completed fan installation. Installation of a VPro Graphics board requires removal of one of the two 90CFM radial exhaust fans (Pabst RER 101-36/12/12A) found in the headless server version of the Origin 350. With the loss of 90CFM of air flow the issue of primary concern when adding graphics to the relatively restrictive confines of the 2U-sized Origin 350 is cooling. The dual 90CFM fans flow enough air that a stock O350 will heat up if run with the case open, while an O350 with one of the exhaust fans removed (and a graphics board installed) will run cooler with the case open.
This Origin 350 graphics conversion used bplaa-yai's method
of removing the processor shroud and installing three fans between the processor node and the VPro graphics board. This method only works with two-processor systems because the fans are positioned where the third and fourth processors would be in a four-processor system. If you have a four-processor Origin 350, or prefer not to remove the processor shroud from a two-processor system, an alternative method of adding VPro graphics is described here: viewtopic.php?f=14&t=16721099
(which is similar in concept to SGI's method of cooling a factory built Onyx InfinitePerformance). Neither method requires making an non-reversible changes to the base Origin 350.
The fan support is a piece of heavy gauge sheet metal angle stock .5"x.5" wide by 10.25" long (the piece of sheet metal angle stock was selected because it closely matches the appearance of rest of the O350 chassis). It's supported on the PCI-side of the O350 by one of the threaded tabs used to secure the case lid, and by a fabricated tab on the power supply side (the tab was added so that the fan support would bisect the chassis at a right angle). The mounting tab on the power supply side is a simple 1" long x .5" wide section of heavy sheet stock with two drilled holes - one end is captured under the screw that closes the power supply cable clamp, the the other end extends outward to support the new fan bracket. The hole drilled hole in the other end of the tab was sized to fit a surplus fan push-pin mount (used to secure the newly added fan bracket to the tab), but a screw and nut would work equally well. To ensure that no contact occurred between the added fan bracket and the power supply cable bundle, the power supply was moved to the outside position (the O350 chassis has provisions for dual power supplies). O350's with a single power supply configuration normally have the power supply installed in the inside position (nearest the node board). In this instance the single power supply was moved to the outside position to ensure the added fan bracket wouldn't make contact with the power supply cable bundle. To prevent any issues with environmental checks done by the L1 controller, the power supply cable bundle was left attached to the same header on the system board (the power supply cable bundle attaches to the power supply with an edge-connector, so the cable bundle can be disconnected at the power supply end and moved there).
The two fans on the outside of the tree-fan array are two 60mm x 25mm Vantec TF6025 Thermoflow temperature controlled fans. These run at between 1900-4200 RPM, 9.9-24.2 CFM and 19-33.5 decibels, and were selected to provide reasonable cooling with minimal additional noise The center fan of the tree-fan array is a 60mm x20mm SuperRed CHA6012CS-A that's rated at 3900 RPM, 19.4 CFM and 29 decibels. The tach wire on the SuperRed is the only one of the three that's wired to the tach pin on the O350 fan connector. The SuperRed was selected because of its static 3900 RPM speed rating. The L1 in the O350 will trigger a (non-fatal) fan warning if the fan attached the the three-pin graphics fan header (located on the system board) drops below 1679 RPM. During a cold start the L1 environmental controller lowers the fan speeds by a percentage of the overall speed rather than to a specific RPM level. That percentage of the 1900 RPM start up speed of the Vantec fans isn't high enough to avoid triggering the warning, so the trick is to select fans that have a speed rating high enough to meet that they'll be above the L1 graphics fan warning level (1679 RPM). The the start up percentage of the fixed 3900 RPM speed of the SuperRed fan is around 1800 RPM (enough to avoid the 1679 RPM L1 fan warning), and even after hours of constant use hasn't exceeded 2200 RPM. At those RPM levels the SuperRed fan isn't noticeable over the original equipment power supply fan or radial exhaust fans, so as an alternative, three SuperRed CHA0612CS-A fans (or a similar fixed speed fan) could be used in all three positions with out adding to the O350's noise footprint.
Regardless of the fans (or cooling method) selected, particular attention should be paid to the fan connection pin-out. The fan header on the O350 system board uses a non-standard pin-out: Pin 1 - 12VDC; Pin 2 - Tach; Pin 3 - Ground (the location of pin 1 is screened on the system board). A 4-pin PWM fan may also be used; the O350 fan header and the PWM fan socket are keyed to allow connection of only the 3 necessary fan wires (although the 12VDC, tach and ground wires should be configured to match the O350 pin-out).
Because the Bedrock ASIC is usually shows up in an L1 'env' query as the hottest part of the system, a low-profile variable-speed thermally-controlled 70mm CPU cooler was added to the top of the Bedrock heat sink (70mm is a perfect fit). The cooler is secured by double-sided foam tape placed between the fan frame and hub and the heatsink. This lowered the Bedrock temperature an average of 8C, and the fan wasn't acoustically noticeable in the running O350.
There's been a few questions in the past concerning support for the VPro PCB. Fuel VPro boards come with a sheet metal support rail screwed to the edge of the board directly opposite of the XIO2 edge connectors. As it comes out of the Fuel that support rail is longer than the VPro PCB by several inches, and as a result would protrude into one of the added cooling fans. The one in the photo has been trimmed so that it was the same overall length as the VPro PCB (using a cut-off wheel, but a hacksaw or even tip-snips would do the job).
File comment: The Origin 350 before modifications. The XIO-2 edge connectors for the VPro graphics board are marked with blue arrows, their position necessitates removal of the radial exhaust fan (just under the tail of the left-most blue arrow). The red arrows indicate the mounting points for the fan bracket that will be added to provide cooling for the processors, Bedrock ASIC and VPro. The metal processor shroud (under the tail of the lower red arrow) will be removed to provide clearance for the heatsink on the VPro board. The yellow arrow points out the location of the unused (until now) 3-pin fan header that controls the graphics board cooling fan. The O350 fan header uses a non-standard pin-out: Pin 1 - 12VDC; Pin 2 - Tach; Pin 3 - Ground. NOTE: A 4-pin PWM fan may also be used; the O350 fan header and the PWM fan socket are keyed to allow connection of only the 3 necessary fan wires (although the 12VDC, tach and ground wires should be configured to match the SGI pinout).
Before.jpg [ 106.9 KiB | Viewed 775 times ]
File comment: This system has a two-processor node board. The solder pads for processors three and four can be seen between the fans and the rear of the VPro board, and illustrate why this method wouldn't work with a four-processor node board - the fans are positioned where the third and fourth processors would be located.
O350_V10-1.jpg [ 497.52 KiB | Viewed 844 times ]
File comment: The cooling array of three 60MM fans just behind the processor and Bedrock heatsinks; and a 70mm CPU cooler positioned on the heatsink of the Bedrock ASIC. The three-fan array pulls air across the heatsinks (away from the viewer); the fan on the Bedrock heatsink blows down.
O350_V10-2.jpg [ 228.59 KiB | Viewed 844 times ]
File comment: A 70mm fan from a low-profile CPU Cooler was placed on the Bedrock heatsink (which is flanked by the processor heatsinks.
O350_V10-3.jpg [ 235.63 KiB | Viewed 844 times ]
File comment: The Fuel VPro graphics board is located towards the top right of the photo. The Fuel version of the VPro board comes with a metal support rail that would extend into the area now occupied by the added cooling fans, so the rail was trimmed to be the same length as the VPro board.
O350_V10-4.jpg [ 486.87 KiB | Viewed 844 times ]
File comment: Top view of the fan bracket. The right end was notched so that the bracket sat entirely on the added support tab (see the next photo) rather than on the power supply cable clamp.
O350_V10-5.jpg [ 467.2 KiB | Viewed 809 times ]
File comment: Bottom view of the fans and bracket. The wiring was run across the bottom of the fans and cable-tied in place. The red arrow indicates the tab added under the power supply cable clamp (to support the fan bracket). The O350 chassis has provisions for dual power supplies. Single power supply configurations normally position the single power supply in the inside position (nearest the node board). In this instance the single power supply was moved to the outside position to ensure the added fan bracket wouldn't make contact with the power supply cable bundle. The power supply cable bundle was left attached to the same header on the system board.
O350_V10-6.jpg [ 522.6 KiB | Viewed 809 times ]