The ASUS ROG Astral LC GeForce RTX 5090 OC Edition (model ROG-ASTRAL-LC-RTX5090-O32G-GAMING) is ASUS's liquid-cooled flagship take on NVIDIA's Blackwell GB202 monster. "LC" means a factory 360mm AIO, and "OC Edition" means a factory overclock. The result, per TechPowerUp, is "the fastest RTX 5090, with the lowest temps and best thermals" of the entire lineup — and, importantly, a much more compact in-case footprint than the giant air-cooled Astral.
Quick verdict: A near-flawless halo card — the coolest (~60–68°C under load), quietest (near-silent), top-performing RTX 5090, with a premium build and genuine per-pin connector safety monitoring. Points come off almost entirely for the ~$3,400 price and the hassle of fitting a 360mm radiator. Score: 93/100.
ASUS ROG Astral LC RTX 5090 OC — Full Specifications
Cross-checked against the ASUS official spec page, NVIDIA, TechPowerUp and HWCooling. The factory boost clocks are officially published by ASUS.
| Specification | Detail |
|---|---|
| GPU & Architecture | |
| GPU chip | NVIDIA GB202 (Blackwell) |
| Process node | TSMC 4NP (4nm-class) |
| CUDA cores | 21,760 |
| RT cores | 170 (4th gen) |
| Tensor cores | 680 (5th gen) — 3,352 AI TOPS |
| Clocks (factory overclocked) | |
| Reference boost clock | 2,407 MHz |
| Astral LC — Default Mode | 2,580 MHz |
| Astral LC — OC Mode (GPU Tweak III) | 2,610 MHz |
| Memory | |
| Memory size | 32 GB GDDR7 |
| Memory speed | 28 Gbps |
| Memory bus | 512-bit |
| Memory bandwidth | 1,792 GB/s |
| Power & Cooling | |
| Default / max power limit | ≈ 600 W (12V-2x6 ceiling) |
| Power connector | 1× 16-pin (12V-2x6 / 600W) |
| Recommended PSU | 1,000 W |
| Cooling | 360mm AIO: copper coldplate + pump on card, 360×38mm radiator with 3× 120mm fans, plus onboard axial fan for VRM |
| Load temperatures | ~60–68°C GPU core / ~68–76°C memory at 600W |
| Noise | Near-silent at default fan curve (≈35 dBA on TechPowerUp's normalized test) |
| Connectivity & Display | |
| Interface | PCIe 5.0 x16 |
| Display outputs | 3× DisplayPort 2.1b + 2× HDMI 2.1b (5 total; max 4 simultaneous) |
| DLSS | DLSS 4 with Multi Frame Generation (up to 4×) |
| Media engine | 3× 9th-gen NVENC, 2× 6th-gen NVDEC, AV1 + 4:2:2 |
| Build & Features | |
| Card (block) dimensions | 288.46 × 153.7 × 48 mm (2.5-slot) |
| Radiator dimensions | 400 × 120 × 65 mm (extra-thick 38mm rad) |
| VRM | 80-amp MOSFETs, military-grade capacitors |
| Features | GPU Tweak III, Power Detector+ (per-pin 16-pin monitoring), dual BIOS, ARGB |
| Availability & Price | |
| Launch | RTX 5090 launch Jan 30, 2025; LC followed shortly after |
| Price | ≈ $3,400 (range ~$2,799–$3,600+) vs $1,999 reference MSRP |
What Makes the Astral LC Special
Vs the Founders Edition: the 360mm AIO runs roughly 18°C cooler than the FE's air cooler at matched load, the factory OC adds ~7% clock (2,610 vs 2,407 MHz), and ASUS's Power Detector+ monitors each pin of the 16-pin connector — a real safety feature given the connector-melting concerns of this generation.
Vs the air-cooled ROG Astral: same factory clocks and 600W ceiling, so out-of-box performance is essentially identical. The win is form factor and acoustics — the LC's card block is a compact 2.5-slot, 288mm unit (heat is exported to the radiator), versus the air model's enormous 3.8-slot, 357.6mm quad-fan body. Many aggregator pages wrongly list the 357.6mm air dimension for the LC — the LC block is much smaller; the 400mm radiator is separate.
Real-World Performance & Thermals
- 4K rasterization: ~41% faster than the RTX 4090, and about 7% faster than the RTX 5090 Founders Edition out of the box.
- Ray tracing + DLSS 4: full 4th-gen RT and 5th-gen Tensor pipeline; DLSS 4 Multi-Frame Generation multiplies effective 4K FPS in supported titles.
- Thermals (the AIO's whole point): ~67°C core / 76°C memory in Cyberpunk 2077 4K+RT at 600W; HWCooling measured as low as ~61.7°C core. Among the coolest 5090s tested.
- Acoustics: near-silent under gaming loads. TechPowerUp's normalized 35 dBA test shows most system noise comes from case fans, not the card.
- OC headroom: roughly +5% on top of the factory OC; the 600W limit (the 12V-2x6 ceiling) is the practical wall, and NVIDIA caps memory OC at +375 MHz.
RTX 5090 Flagships Compared
| Spec | ASUS ROG Astral LC OC | MSI Lightning Z | RTX 5090 Founders Edition |
|---|---|---|---|
| Factory boost | 2,610 MHz | 2,775 MHz | 2,407 MHz |
| Power limit | 600 W | 800–1,000 W | 575 W |
| Cooling | 360mm AIO (2.5-slot block) | 360mm AIO | Dual flow-through air |
| Load temp | ~60–68°C | Low (AIO) | Higher (air) |
| Recommended PSU | 1,000 W | 1,600 W+ | 1,000 W |
| Availability | Limited retail | Lottery (1,300 units) | Retail |
| Price | ≈ $3,400 | $5,090.99 | $1,999 MSRP |
What Buyers Ask
- "Is ~$3,400 worth a 70% premium over the $1,999 reference?" If you want the coolest, quietest 5090 with a compact in-case footprint and a premium build, yes — but you're paying for thermals and acoustics, not a big FPS jump.
- "LC vs the air-cooled Astral?" Same clocks; the LC is cooler, quieter, and frees up case space — choose it if you can mount a 360mm radiator.
- "vs MSI Suprim/Lightning or Gigabyte Aorus Waterforce?" The Astral LC is among the best-balanced liquid 5090s for temps and noise without the Lightning Z's lottery and 1,600W demands.
- "Do I need a 1,000W PSU?" Yes — ASUS recommends 1,000W with a native 12V-2x6 / ATX 3.x cable for the 600W card.
- "Will the radiator fit my case?" The most important fit question: you need clearance for a 400mm-long, 38mm-thick 360mm radiator plus the 2.5-slot block.
- "Is the connector safe?" ASUS's Power Detector+ monitors each 12V-2x6 pin individually — genuine peace of mind this generation.
Pros and Cons
✅ Pros
- Among the coolest RTX 5090s (~60–68°C core under load)
- Near-silent under load (≈35 dBA on TechPowerUp's normalized test) despite 600W heat output
- Factory OC (2,580/2,610 MHz) + 600W limit for top-tier sustained performance
- Compact 2.5-slot block frees up case space vs giant air 5090s
- Premium build: 80A MOSFETs, military-grade caps, dual BIOS
- Power Detector+ per-pin 16-pin monitoring (real safety value)
- Extra display flexibility (3× DP 2.1b + 2× HDMI 2.1b), 32GB GDDR7
❌ Cons
- Expensive — ~$3,400, roughly 70% over reference MSRP
- Needs a case that can mount a 400mm-long 360mm AIO
- Out-of-box gains over a Founders Edition are modest (~7%)
- AIO adds a pump as a long-term failure point and complicates install
- 1,000W PSU + proper 12V-2x6 cabling effectively mandatory
- Availability/scalping make real street price unpredictable
The Bottom Line
The ASUS ROG Astral LC RTX 5090 OC Edition is a near-flawless execution of a flagship: the coolest, quietest, top-performing RTX 5090 you can buy, with a premium build and genuine connector-safety features — in a far more case-friendly package than the air-cooled Astral. Points come off only for the steep price and the practical need to fit a 360mm radiator. As a no-compromise flagship it's outstanding. Our score: 93/100.
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Frequently Asked Questions
What is the boost clock of the ASUS ROG Astral LC RTX 5090 OC?
ASUS officially lists 2,580 MHz in Default Mode and 2,610 MHz in OC Mode (enabled via GPU Tweak III), versus the RTX 5090 reference boost of 2,407 MHz — about a 7% factory overclock.
How cool and quiet is the ASUS Astral LC RTX 5090?
It's among the coolest and quietest RTX 5090s tested — roughly 60–68°C GPU core under a 600W load (HWCooling measured as low as ~61.7°C) and near-silent (≈35 dBA on TechPowerUp's normalized test), thanks to its 360mm AIO with an extra-thick 38mm radiator.
Will the ASUS Astral LC radiator fit my case?
You need room for a 360mm radiator that is 400mm long and 38mm thick (plus tubing), as well as space for the 2.5-slot, 288mm card block. Check your case's 360mm AIO mounting clearance before buying — it's the most common fit issue.
ASUS Astral LC vs the air-cooled ROG Astral RTX 5090 — which is better?
They share the same 2,580/2,610 MHz factory clocks and 600W ceiling, so performance is essentially identical. The LC runs cooler and quieter and uses a compact 2.5-slot block (vs the air model's 3.8-slot, 357.6mm quad-fan body), but requires room for a 360mm radiator.
How much does the ASUS ROG Astral LC RTX 5090 OC Edition cost?
Around $3,400 at review, with retail listings ranging roughly $2,799 to $3,600+ — about a 70% premium over the RTX 5090's $1,999 reference MSRP. Pricing varies with availability and scalping.
