Intel Core Ultra 200S · LGA1851 / Dual-tower air cooler
Does the Thermalright Peerless Assassin 120 SE fit the Core Ultra 5 245K?
Yes. The Thermalright Peerless Assassin 120 SE fits the Core Ultra 5 245K with 86 W of thermal headroom; we estimate 74 °C under sustained load and 52 °C while gaming, an excellent match.
Reviewed by Farrukh Sufyan SarwarHow we estimate temperaturesPublished Prices verified
Full load
74°
Gaming
52°
Idle
32°
Excellent fit
Safe at 74 °C full load
26 °C below the 100 °C junction limit under a sustained all-core load.
The Thermalright Peerless Assassin 120 SE is an excellent match for the Core Ultra 5 245K, with 86 W of headroom above its 159 W boost ceiling. We estimate 52 °C in games and 74 °C under a full all-core render, leaving quiet-fan-curve room.
Thermal estimate
Both figures assume a 35 °C case-internal ambient and the cooler's sustained rating; the CPU's own junction limit caps the full-load figure.
| Load | Estimate |
|---|---|
| Idle | 32 °C |
| Gaming | 52 °C |
| Full load | 74 °C |
| Junction limit | 100 °C |
- 0–85 % comfortable
- 85–100 % fans ramp
- 100 %+ throttles
- Thermal headroom
- +86 W
- CPU boost / gaming draw
- 159 W / 90 W
- Cooler sustained rating
- 245 W
- Junction limit
- 100 °C
- Cooler height
- 155 mm
- RAM clearance
- 42 mm
- Sockets in the box
- AM4 · AM5 · LGA1200 · LGA1700 · LGA1851
What the numbers mean for this build
- 01
86 W of sustained headroom
The Core Ultra 5 245K uses 65 % of the Thermalright Peerless Assassin 120 SE's rated capacity at its 159 W ceiling, which means the fans can run a relaxed curve and stay quiet even in Cinebench.
- 02
RAM clearance 42 mm
Most heatspreader kits up to 42 mm slide under the front fan without moving it. Check the first DIMM slot on boards with the socket placed close to the memory.
Will it physically fit?
Drag the sliders to your memory height and case limits. The schematic moves with you and shows where the Peerless Assassin 120 SE clashes.
Stock front-fan clearance on the Peerless Assassin 120 SE: 42 mm.
Listed as “CPU cooler clearance” in the case spec sheet. This cooler is 155 mm tall.
- RAM heightClash (-2 mm)
Modules sit 2 mm too tall. Raise the front fan or choose 34 mm low-profile RAM.
- Cooler height vs caseFits (+10 mm)
10 mm between the cooler and the side panel.
Overall Clash for the Peerless Assassin 120 SE with your inputs.
Schematic, not to product scale.
Buy it, or compare the alternatives
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This pairing
$29.42as of Sep 17, 11:38 PM UTC · In Stock
ThermalrightPeerless Assassin 120 SE
Dual-tower air cooler · 155 mm
245 W rated, 86 W headroom on the Core Ultra 5 245K.
Top air value
$26.99as of Sep 17, 11:38 PM UTC · In Stock
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101 W headroom for about $27
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ThermalrightFrozen Infinity 360
360 mm AIO liquid cooler · 52 mm
Estimated 63 °C under full load with quiet fan curves
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ThermalrightAXP120-X67
Low-profile air cooler · 67 mm
67 mm tall and still 99 °C at full load
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product.
Terms used on this page
- Thermal headroom
- The cooler's sustained dissipation rating minus the CPU's boost power limit, in watts. Positive headroom lets fans run slower and quieter; 25 W or more is rated Excellent here.
- TjMax
- The maximum junction temperature (typically 95–100 °C, 89 °C on Ryzen X3D parts). At TjMax the CPU throttles clocks to stay in place; it will not overheat, but it will lose performance.
- PL1 / PL2
- Intel's two power limits. PL1 (Processor Base Power) is the sustained draw the CPU settles at; PL2 (Maximum Turbo Power) is the short-term boost ceiling. Many desktop boards run PL2 indefinitely, so a cooler must be sized for PL2, not PL1.
- Thermal throttling
- Automatic clock reduction when the CPU hits TjMax. A pairing is flagged as a throttling risk when the modelled full-load temperature reaches the junction limit or the cooler is rated 15 W or more below the CPU's boost power.
- RAM clearance
- The tallest memory module that fits under an air cooler's front fan in its stock position. Dual-tower coolers with less than 42 mm clash with tall RGB kits (typically 44 mm) unless the fan is raised.
- CPU cooler height
- The installed height of an air cooler from the motherboard, compared against the case's published CPU cooler clearance. Coolers at or above 160 mm exclude many compact Micro-ATX and tempered-glass mid-towers.
- Dual-tower air cooler
- An air cooler with two fin stacks and a fan between them (often a second in front). Highest air-cooling capacity, but the front fan overhangs the DIMM slots, which is where RAM clearance limits come from.
Frequently asked questions
Will the Thermalright Peerless Assassin 120 SE keep the Core Ultra 5 245K from thermal throttling?
Yes. The estimated full-load temperature is 74 °C, 26 °C below the 100 °C throttle point.
What temperature should I expect while gaming on the Core Ultra 5 245K with this cooler?
Around 52 °C with a 35 °C case ambient, because GPU-bound games only draw about 90 W from the CPU package. Cooler rooms and better case airflow lower that figure.
Does the Thermalright Peerless Assassin 120 SE fit tall RGB RAM?
Modules up to 42 mm clear the front fan in its stock position. 44 mm kits require raising the fan.
Is the Thermalright Peerless Assassin 120 SE compatible with the LGA1851 socket?
Yes, LGA1851 hardware is included. Supported sockets: AM4, AM5, LGA1200, LGA1700, LGA1851.
Hubs: Core Ultra 5 245K · Thermalright Peerless Assassin 120 SE · LGA1851