Chassis builds

Two cards fit in most desktops with a shroud and a pair of fans. Past four cards the questions change: where the air comes from and where it goes, how many circuits you have, and how loud the room can be. This page collects the builds people posted, with their cooling and power. Photos were posted in the linked Discord messages; the descriptions below are the posters' own words, since the images are not part of the import.

Ivan's eight-card server

Reported Built by @darkmaniac7 (Ivan), notes from 2026-10-26 to 10-29. Source: @darkmaniac7, 2026-10-27 (lab notes)

Hardware. A 4U eight-GPU server with two CPUs and four cards per CPU in direct-attached slots; eight 8 GB cards unlocked to 64 GB with Gen2 x16 links. Power from the chassis's redundant server PSUs on a dedicated 240 V circuit behind a 3,000 VA UPS.
Airflow. Two rear fans plus a fan wall of eight fans across the middle of the chassis, all on the BMC. In its automatic mode the BMC reads the GPU temperatures and drives the GPU zone to 100 % at about 80 C, which is very loud.
Fan control. A script puts the BMC in manual (Full) mode and writes one duty to all four fan zones every 30 seconds: base 10 to 20 %, 40 % when the board reaches 60 C or a GPU 88 C, 100 % at 70 C board or 92 C GPU. Measured speeds: the rear fans floor at 1,260 rpm (10 % and 20 % give the same) and reach 3,640 rpm at full; the wall fans run 2,240 rpm at 10 %, 3,220 rpm at 20 % and 3,780 rpm at 25 %.
Power governor. GPU heat is handled by the power cap, not the fans. Every 60 seconds a timer reads the chassis inlet temperature from the BMC and the GPU temperatures:
- inlet above 27 C or any GPU above 80 C: lower every card's cap by 10 W (floor 110 W);
- inlet below 24 C and every GPU below 72 C for three checks in a row: raise it by 10 W (ceiling 250 W).
- With caps at 250 W the box draws about 2.0 kW; the cards read 63 to 79 C in the first 20 seconds. In daily use the governor holds the caps between 180 and 230 W.
What it showed.
- With only the two rear fans running at their floor, the governor walked the caps down from 250 W to 160 W (hottest GPU 81 C).
- Raising the wall from 10 % to 25 % did not cool the hottest cards: they stayed at 84 to 85 C while the governor cut from 240 to 200 W, and the inlet air climbed from 24 C to 26 C. About 2 kW was heating the room; the room, not the fan wall, was the limit.
- Slot position matters more than fan speed: at the same 180 W and 20 % fans, two of the four cards per CPU ran 81 to 84 C and the other two 58 to 68 C. Under a lighter 150 W load the split was the same (51 to 54 C against 40 to 43 C). Those hot slots are the ones to re-space.
- The fan wall was later unplugged until a fan-to-heatsink contact problem is fixed.
Traps hit.
- Reported BMC Full mode survives a power loss but the duty does not, so the next power-on ran every fan at 100 % (at night). Now the BMC rests in automatic mode, a shutdown hook hands the fans back before the OS goes down, and the power-restore policy keeps the box off after an AC loss. PixelML/club-170hx documents the same lesson on a Supermicro BMC. Source: repo github.com/PixelML/club-170hx by PixelML on GitHub, posted by @c133, 2026-10-20 (Apache-2.0 license)
- A fan below about 420 rpm makes the BMC flag a fault and hold 100 % until AC is removed, so the script never writes less than 10 %. On every boot the BMC flips the first manual write back to 100 % once; the 30-second re-check catches it. Fan header names changed after a re-plug, so never key a script on a header name.
- Warning The boot and model NVMe sat on a PCIe-to-M.2 adapter with no airflow beside eight hot cards. During the heaviest sustained read it had seen (streaming about 189 GiB of model tables) the drive dropped off the bus and the box would not boot until it was reseated; the system journal was lost with the filesystem. With a fan and then a heatsink on the drive it peaked at 36 C at 250 MB/s, against 81 C at 450 MB/s before; model loads now wait for the drive to cool to 55 C and pause at 79 C. Source: @darkmaniac7, 2026-10-29 (lab notes)
Results on this box are on Recipes and Benchmarks; the power data is on Undervolting and power limits.

Servers

Reported Gigabyte G292-Z20 (2U, single socket, eight GPU slots, about $500): "a steal for 8cmp setup" Source: @neapopa, 2026-10-25; units around $500 Source: @voidgiraffe, 2026-10-15. @cmdrwaka324 runs five CMP 170HX, two RTX 3090 and an Intel B60 in one: good BIOS and out-of-band management, an aggressive fan tune that still idles "like a big box fan at near full speed", and all cards stay cool even in a summer garage. Each GPU pair sits on its own PCIe switch, so P2P is fast within a pair and slower between pairs. Source: @cmdrwaka324, 2026-10-25 @danske1: it handles eight cards in 2U, the stock fans are ear-piercing (fine for a warehouse), and you need EPS-to-EPS cables because adapters do not fit in the back section. Source: @danske1, 2026-10-26 A fan-tuning script exists, but the floor is still about 3,750 to 4,000 rpm Source: @a1rm4x, 2026-10-15
Source: @voidgiraffe, 2026-10-15. The 4U G482-Z52 is dual socket, so half the cards cross the socket to reach the others; check the system diagram. Source: @cmdrwaka324, 2026-10-26 See Gigabyte G292-Z20.
Reported Supermicro SYS-4028GR: too loud even in a garage, and about 300 W with no load, mostly the fans. Source: @catchyuser, 2026-10-09 Supermicro 1028GQ-TRT (1U): nine FAN-0163L4 fans, about 85 dBA; its owner colocates it. Source: @programmerboi, 2026-10-09
Reported 2U Supermicro, one card at 250 W: 3 A 80 mm fans were not enough until the gridded slot brackets were taped over (10 C cooler, stable); "it wants 3A min". Source: @mlx4, 2026-10-20 Four such fans can draw 200 W. Source: @mlx4, 2026-10-20
Contested Four cards in a GPU server with empty slots (photo posted Source: @lamune6809, 2026-10-20): fill every slot or print shrouds Source: @zorg33, 2026-10-20, or just seal the openings Source: @markshowa, 2026-10-20.
A Gigabyte server "on idle its screaming but then on a 20-60% load quiet as can be" on 220 V. Source: @sojun80, 2026-10-21
Fan control on servers: see Fans and ducts. A BMC cannot see a card on a passive riser. Source: @fafinet, 2026-10-21

Cases

Reported FSP U500 with a custom sliding plenum: @alanoo's two- and three-card builds, a dual-fan four-card plenum printing; cheap but well made; no display output used. Photos posted. Source: @alanoo, 2026-10-24 His four cards run at 200 W, at most 62 C in a garage. Source: @alanoo, 2026-10-26
Reported EK-Fluid Works V3000: four cards on two dual-card AIOs with 480 mm radiators; a fifth card needs a case mod. Source: @globalapathy, 2026-10-18 See Water cooling.
Reported RM52 case: dual 80 mm fans at the back and more right above the cards. Source: @ikyo, 2026-10-11
Reported Sandwiched cards with a shared intake: 34 to 42 C under load (photo posted). Source: @daveedcoles, 2026-10-11
Source: @moliminous, 2026-10-11
Reported Dell T5810 as a host: you need unusual cables just to power one CMP, the fan PWM controls are locked on Linux, and there is little room in front of the card. Source: @kellertreppe123, 2026-10-07 Branded workstations lock you into their parts; swapping their PSUs can start fires. Source: @endsjeremy, 2026-10-07
An AIO-cooled card in a desktop: riser cable, OCuLink from an M.2 slot, or the radiator outside the case. Source: @robbbbbb7973, 2026-10-18
Source: @globalapathy, 2026-10-18
Source: @boz._., 2026-10-18
Reported Three cards in an ATX "sleeper" case (@pekoraali, photos posted). Everything fits in a nearly standard ATX case with 8 expansion slots. Cooling: two Arctic P14 Pro in push-pull at 40 to 50 % (about 1,500 rpm each), the other case fans at 20 to 30 %; the exhaust P14 Pro sits on a piece of cardboard with cut-outs for the cards' exhaust vents, almost every gap is sealed with tape or foam, and unused case openings are foamed to stop recirculation. Cardboard is easy to cut to an unusual layout and a fine stopgap, but a printed shroud made for the case is the better answer. Power: 120 W cap, spikes to 130 to 160 W; two cards take 2x 8-pin PCIe into the bundled EPS adapter and the middle card a direct PSU-to-EPS cable that clicked in snugly, five 8-pin cables in all from a 1,300 W class PSU (similar to an NGDP 1300W). Result: 69 to 79 C under test load, fine for winter but not summer; he would like 140 to 150 W under 75 C. Noise is mostly air through the copper fins plus a high-pitched VRM chirp. One card had been serviced before (green liquid pads on the VRM) and two had dried paste; he left the paste alone after once knocking an SMD capacitor off a 5700 XT while removing a fused heatsink. He rates the build below average. Source: @pekoraali, 2026-10-19
Theory Mountain Mods Ascension with a custom loop (@siriusrhi's plan, nothing built yet): five cards at x16 with two x8 slots left for a 25GbE NIC, or six cards if one drops to Gen2 x8; the case holds two 360 mm radiators plus a 480 mm one, and two PSUs. He chose a loop over ready-made liquid-cooled cards because those need one AIO and 240 mm radiator per card (see Water cooling#All-in-one coolers). Source: @siriusrhi, 2026-10-25
Source: @siriusrhi, 2026-10-25 His question whether standard A100 blocks fit is answered on Water cooling#Blocks that fit. Source: @siriusrhi, 2026-10-25

Open frames and racks

Mining frames: @endsjeremy likes the miningeek open frames; one Chinese maker sells them under many names, so custom parts and bulk orders are possible. Source: @endsjeremy, 2026-10-09 With two to six cards the usual chassis plan falls apart; a double-layer open frame is an option. Source: @ob88594, 2026-10-09
2020 aluminium extrusion with a 3D printer and M2/M3 screws. Source: @mountains1605, 2026-10-21
A $25 AL03 open-air ATX test bench (not stackable; about $35 for a stackable one). Source: @globalapathy, 2026-10-21
A test bench at the bottom of an AWAVE mining rack with risers up to the cards, going into a high-airflow noise box for about 10 dB less. Source: @impactic, 2026-10-22
Two AliExpress mining frames Source: @con3po7016, 2026-10-21; an eBay server rack, "surprisingly effective" Source: @_syn_thetic_, 2026-10-25; a 12-GPU rack like this eBay listing, found locally for $20 Source: @gnasherrr, 2026-10-25.
A small printed plate (frontplateminimal.stl) ties the backs of four cards into one block when the fronts share an intake shroud; see Fans and ducts. Source: @mountains1605, 2026-10-11

Larger builds

Reported Twelve cards on a few dedicated circuits with an air conditioner pointed at them: still the warmest and loudest room in the house (photos posted). Source: @gpmickey, 2026-10-19 @gpmickey added three 115 V 20 A breakers for them. Source: @gpmickey, 2026-10-20
Reported Octominer X12 Ultra: @segmond runs twelve cards with only the cards in the case (motherboard and the rest outside); the case holds, powers and cools the cards, the stock fans are moved outside and a script sets them from GPU temperature, no extra fans needed. @reala7096 put motherboard, PSUs and cards all in the same case with only the rear fans and the CPU radiator outside, and printed a pull-fan front shroud for it (see Fans and ducts). @cibernox asked for printed front shrouds that add pull fans. Source: @cibernox, 2026-10-15
Source: @reala7096, 2026-10-15
Source: @segmond, 2026-10-15 See also Octominer X12 Ultra builds.
Reported Eight cards with printed push and pull plenums (@neapopa). Before the plenums, three push and three pull Delta server fans at 100 % held 175 W with the hottest card at 70 C and the rest at 60 C. The plenums (STL files on Fans and ducts) slot tightly onto the stack with no air leakage; the rear one needs the slot brackets removed. A temperature screenshot after 20 minutes of load on stock paste was posted. Fans: Delta AFB1212SHE in front and Bitmain L3+ fans for exhaust, six fans drawing 11 to 12 A; "works great as a white noise machine". Power: HP 1,200 W 94 % efficient server PSUs with custom soldered cables, four cards per PSU. Source: @neapopa, 2026-10-22
Reported Eight cards with eight 80 mm fans in push-pull, "very quiet". Source: @con3po7016, 2026-10-08
Reported Eight water-cooled cards in single-slot blocks, a first PC build. Source: @djpandaman, 2026-10-08
Reported Eight cards for the full GLM-5.3 at 200 W each "using a cardboard box fan shroud and duct-tape". Source: @1a2b3c0967, 2026-10-08
Reported Five cards on a 5-GPU PCIe switch board with slim printed housings, 33 to 37 C. Source: @moliminous, 2026-10-10 Five cards on an external GPU switch baseboard next to six RTX 3090s needed a 180 W cap to stop PCIe drops on large prompts. Source: @moliminous, 2026-10-19
Reported Four cards on a 5-slot PCIe switch with the middle slot empty, one P12 Pro per pair. Source: @cibernox, 2026-10-07
Reported 18 or more cards on a ground-cooled liquid loop at 230 W that heats the house. Source: @rh3dai, 2026-10-14

Air in and out of the room

An insulated intake box with two 100 mm hoses was not enough: the rig needs 3 to 5 times that air, so it now sits open to cold outdoor air. Source: @finishtilt14, 2026-10-15
Theory Put the loud fan elsewhere: an inline duct fan exhausting the box from outside the room. Source: @roboalchemist., 2026-10-26
Source: @endsjeremy, 2026-10-26
Basements and garages are where most of the loud builds live. Source: @catchyuser, 2026-10-09
Source: @civiloid, 2026-10-16

Power distribution

Plan circuits before cards: see Power supplies and cabling for PSU sizing per card count, 240 V circuits, surge protection and UPS limits, and Power and cabling warnings for what has burned.