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Peerless Assassin RAM Clearance: Will Your Kit Fit? (2026)
Yes, with a gate. The Thermalright Peerless Assassin 120 SE gives you 42 mm of RAM clearance in its stock configuration. Any DDR5 kit under that height slides under the front fan without a thought. Anything taller fouls it.
Raise the front fan and you get about 55 mm, which covers most RGB kits. That trade is not free. The cooler already stands 155 mm, so lifting the fan pushes the whole assembly higher and you give back in case top-panel clearance what you gained in memory clearance.
At a glance
Configuration | RAM clearance | Cooler height | What it costs you |
|---|---|---|---|
Stock, front fan seated low | 42 mm | 155 mm | Nothing. This is the rated fit. |
Front fan raised one row | About 55 mm | Above 155 mm | Case top-panel clearance and some airflow over the lower fins |
Stock, front fan seated low
- RAM clearance
42 mm
- Cooler height
155 mm
- What it costs you
Nothing. This is the rated fit.
Front fan raised one row
- RAM clearance
About 55 mm
- Cooler height
Above 155 mm
- What it costs you
Case top-panel clearance and some airflow over the lower fins
Verdict: Peerless Assassin RAM clearance by kit height
Memory kit | Module height | Stock, 42 mm | Fan raised, 55 mm | Buy |
|---|---|---|---|---|
31.5 mm | Clears | Clears | ||
34.9 mm | Clears | Clears | ||
Low-profile non-RGB kits | 31 to 35 mm | Clears | Clears | Not applicable |
Standard RGB kits | 42 to 45 mm | Fouls the fan | Clears | Not applicable |
Tall enthusiast kits | 50 mm and up | Fouls the fan | Fouls the fan | Not applicable |
- Module height
31.5 mm
- Stock, 42 mm
Clears
- Fan raised, 55 mm
Clears
- Buy
- Module height
34.9 mm
- Stock, 42 mm
Clears
- Fan raised, 55 mm
Clears
- Buy
Low-profile non-RGB kits
- Module height
31 to 35 mm
- Stock, 42 mm
Clears
- Fan raised, 55 mm
Clears
- Buy
Not applicable
Standard RGB kits
- Module height
42 to 45 mm
- Stock, 42 mm
Fouls the fan
- Fan raised, 55 mm
Clears
- Buy
Not applicable
Tall enthusiast kits
- Module height
50 mm and up
- Stock, 42 mm
Fouls the fan
- Fan raised, 55 mm
Fouls the fan
- Buy
Not applicable
How we checked the gate
Thermalright publishes the cooler's dimensions but not a memory clearance figure. The 155 mm height, the six 6 mm heatpipes and the pair of TL-C12C 120 mm fans come straight off the product page. The 42 mm number comes from where the front fan's lower edge sits once the cooler is mounted, and it is the figure that has held up across repeated owner measurements.
Memory heights came from vendor spec sheets and a measured height table, not from product photos. Heights vary inside a single brand. Crucial's Pro line sits at 31.5 mm while the Pro Overclocking modules run closer to 35 mm, and Kingston's FURY Beast is 34.9 mm in black aluminum but 42.2 mm once the RGB diffuser goes on. Same family name, different outcome, and the SKU letter is what decides whether the cooler goes on.
The gate itself is the same shape as every other clearance question. We ran the same question for an NH-D15 G2 in a Corsair 4000D the same way: find the published dimension, find the real-world obstruction, and report the number instead of a reassurance.
Clears it stock: Crucial Pro DDR5-6000 32 GB
Specs
Capacity | 32 GB (2 x 16 GB) |
Speed | DDR5-6000 |
Latency | CL48 |
Module height | 31.5 mm |
Heatspreader | Low-profile aluminum, no RGB |
Headroom under stock fan | 10.5 mm |
Platforms | AM5, LGA 1700 and 1851 |
Capacity
32 GB (2 x 16 GB)
Speed
DDR5-6000
Latency
CL48
Module height
31.5 mm
Heatspreader
Low-profile aluminum, no RGB
Headroom under stock fan
10.5 mm
Platforms
AM5, LGA 1700 and 1851
What it does well
At 31.5 mm this is the shortest kit in the comparison, and it leaves 10.5 mm of air between the top of the module and the underside of the front fan. That margin matters more than it sounds. You can pull the fan for a dust clean and drop it back on the clips without measuring anything first.
The speed bin is the ordinary one. DDR5-6000 is what AM5 wants for a clean 1:1 fabric ratio, and Crucial lists the kit as compatible with both recent Intel platforms and Ryzen 7000, so a board reads its profile without a manual subtimings pass.
What you give up
CL48 is loose. Against a 6000 CL30 kit you are giving up real latency, and in cache-sensitive games that gap shows up in 1% lows rather than averages. If the build is an X3D chip chasing frame pacing, this is not the kit.
There is no RGB, which is the point, but it also means the kit disappears in a windowed build. Crucial also sells a Pro Overclocking line under nearly the same brand words, and reports put those modules closer to 35 mm. They still clear, but they eat most of the margin, so check the part number rather than the family name.
Who it's for
Someone mounting a Peerless Assassin on a Ryzen 7000 or 9000 build who wants the clearance question closed and never reopened. If you are buying the cooler and the memory in the same order, this is the pairing with the least to go wrong. For a wider shortlist, our roundup of low-profile DDR5 kits carries the rest of the band.
Clears it stock on EXPO: Kingston FURY Beast DDR5-6000 32 GB
Specs
Capacity | 32 GB (2 x 16 GB) |
Speed | DDR5-6000 |
Latency | CL36 |
Module height | 34.9 mm |
Heatspreader | Black aluminum, non-RGB |
Headroom under stock fan | 7.1 mm |
Profile | AMD EXPO |
Capacity
32 GB (2 x 16 GB)
Speed
DDR5-6000
Latency
CL36
Module height
34.9 mm
Heatspreader
Black aluminum, non-RGB
Headroom under stock fan
7.1 mm
Profile
AMD EXPO
What it does well
CL36 at 6000 is the timing set most AM5 builders want, and the EXPO profile means one BIOS toggle rather than a manual tuning session. At 34.9 mm the black aluminum heatspreader still slides under the stock fan with 7.1 mm to spare.
Kingston's spread on this family is wide, so the same product name exists at 5200, 5600, 6000 and above. The 6000 CL36 EXPO bin is the one that matches an AM5 board's comfortable fabric ratio without turning memory into a lottery.
What you give up
Seven millimetres is a smaller cushion than the Crucial kit's ten. It clears, but if you later swap to a cooler whose front fan sits lower, there is less room to absorb the change.
The bigger risk is the name. Kingston sells FURY Beast and FURY Beast RGB side by side, and the RGB module measures 42.2 mm. That is two tenths of a millimetre over the stock gate, which is the kind of miss builders discover with the cooler half-mounted. Buy the non-RGB SKU deliberately.
Who it's for
AM5 builders who want 6000 CL36 and a one-click EXPO profile without giving up stock clearance. If tighter timings matter more to you than three extra millimetres of headroom, take this over the Crucial kit.
The cooler itself: Thermalright Peerless Assassin 120 SE
Specs
Height | 155 mm |
RAM clearance, stock | 42 mm |
RAM clearance, fan raised | About 55 mm |
Heatpipes | 6 x 6 mm |
Fans | 2 x TL-C12C 120 mm PWM |
Weight | 730 g plus 120 g per fan |
Sockets | AM4, AM5, LGA 115X/1200/1700/1851 |
Height
155 mm
RAM clearance, stock
42 mm
RAM clearance, fan raised
About 55 mm
Heatpipes
6 x 6 mm
Fans
2 x TL-C12C 120 mm PWM
Weight
730 g plus 120 g per fan
Sockets
AM4, AM5, LGA 115X/1200/1700/1851
What it does well
Six 6 mm heatpipes, two towers, two PWM fans and a mounting kit that covers AM4, AM5 and every recent Intel socket. That is flagship air-cooler hardware at an impulse price, which is why the Peerless Assassin shows up in nearly every budget build list. A 9700X or a 14600K sits comfortably under it.
The fans are Thermalright's own TL-C12C units, 120 mm across and 25 mm thick. At mid duty they are quiet enough that the cooler is not the loudest thing in the case.
What you give up
The geometry is the cost. The front fan hangs over the first DIMM slot, which is the entire reason this page exists, and there is no offset mount to slide the tower back. At 155 mm it also sits close to the ceiling of a standard mid-tower, so a case rated for 160 mm leaves you five millimetres and no room to raise the fan.
The heatsink alone weighs 730 g, with another 120 g per fan. On a horizontally mounted board that is real hanging mass on the socket. If you need something shorter, our low-profile cooler height chart has the alternatives.
Who it's for
Budget and mid-range builders who want most of a flagship air cooler's performance and are picking their memory at the same time. Buying both together is what turns the clearance number into a planning detail instead of a return. If you have not settled the air versus liquid question yet, how to choose a CPU cooler is the decision that comes first.
If your RAM is already tall: Thermalright Frozen Notte 240 ARGB
Specs
Type | 240 mm all-in-one liquid cooler |
Radiator | 240 mm |
Fans | 2 x 120 mm PWM ARGB |
Bearing | S-FDB |
RAM clearance | Unrestricted |
Sockets | AM4, AM5, LGA 115X/1200/1700/1851/2011 |
Type
240 mm all-in-one liquid cooler
Radiator
240 mm
Fans
2 x 120 mm PWM ARGB
Bearing
S-FDB
RAM clearance
Unrestricted
Sockets
AM4, AM5, LGA 115X/1200/1700/1851/2011
What it does well
A 240 mm radiator moves the heat exchanger off the board entirely. Nothing sits over the DIMM slots, so a 44 mm RGB kit or a 51 mm enthusiast kit stops being a compatibility question at all. Cooling capacity lands in the same band as the Peerless Assassin.
The pump block is low, the fans are ordinary 120 mm PWM units, and socket support covers AM4, AM5 and the recent Intel sockets, so the bracket you need is already in the box.
What you give up
A pump is a moving part with a service life. Buyers have flagged AIO pumps failing several years in, and a pump that quits does not degrade gracefully the way a slowing fan does. That risk is the honest trade for the clearance you gain.
You also need a case with a 240 mm mounting position, plus a fan header and an ARGB header you may not have budgeted for. If you would rather stay on air and simply need more thermal headroom, our guide to air coolers built for more heat covers that path.
Who it's for
Someone who already owns a tall RGB kit and would rather change the cooler than the memory. It is also the right call when the case top panel sits too close to allow raising the Peerless Assassin's front fan.
Bottom line
If you are buying the cooler and the memory together, buy the Crucial Pro DDR5-6000 32 GB and stop thinking about it. If you want 6000 CL36 on EXPO and can live with a smaller cushion, buy the Kingston FURY Beast non-RGB kit. If your kit is already 42 mm or taller, raise the front fan only when your case has the headroom, and switch to the Frozen Notte 240 when it does not.
The Peerless Assassin itself is still the right air cooler at this price. Clearance is the one thing it asks you to plan around, and picking a PSU, cooler, and case together is where that planning starts.
FAQ
What is the RAM clearance on a Peerless Assassin 120 SE?
42 mm in stock configuration. That is the distance between the DIMM surface and the underside of the front fan once the cooler is mounted. Raise the front fan a row on its clips and the figure goes to roughly 55 mm, but the whole assembly then sits above the cooler's rated 155 mm height. Check your case's CPU cooler clearance before you plan on the raised figure.
Will the Peerless Assassin fit RGB RAM?
Usually not in stock configuration. Most RGB DDR5 kits land between 42 mm and 45 mm because the light diffuser adds height above the heatspreader, which puts them at or over the 42 mm gate. Kingston's FURY Beast RGB measures 42.2 mm and fouls by fractions of a millimetre. Raising the front fan clears almost all of them. If you want RGB and stock clearance, look for a kit that keeps the diffuser inside a 40 mm module.
Can you raise the front fan on a Peerless Assassin?
Yes. The fans hang on wire clips that hook into the fin stack, and moving the front fan up a row is a thirty-second job with the cooler still mounted. You gain roughly 13 mm of memory clearance. What you lose is case clearance, because the fan then extends above the top of the tower, plus a little airflow across the lower fins where the hot air actually sits.
Does the Peerless Assassin block RAM slots on AM5?
It overhangs the first slot rather than blocking it. On AM5 boards the DIMM slots sit close enough to the socket that the front fan ends up above slot A1, so the question is height and not access. A kit at or under 42 mm installs normally in all four slots. A taller kit physically stops the fan from seating at its lowest position.
What is the tallest RAM that fits under a Peerless Assassin?
42 mm with the fan at its stock position, and about 55 mm with the fan raised. In practice that means anything in the low-profile band clears without thinking, standard RGB kits need the fan raised, and enthusiast kits above 50 mm are a coin flip even then. Modules over 55 mm do not fit in any configuration, and those builds need a low-profile kit or a liquid cooler.
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