Why do GPUs run hotter than CPUs?

hat1324 · Sep 4, 2014

Or rather, the temperature seems to fluctuate far more dramatically.

My i5 will idle at around 50C (curse you Haswell) but will only peak off at about 70 under load. On the other hand, my R9 280X equipped with a Corsair H55 will idle at around 40C but can max at 82C at full load.

I've had similar experience with previous high end cards. What happened to the days of passively cooled graphics?

XL-R8R · Sep 4, 2014

Your card is pulling around 200 - 300w. Your CPU around 50 - 80w max, even in IBT or something similar.

If you are indeed using an H55 to cool your card and are still getting 82'C fully loaded; something is wrong. A standard 280X with aftermarket OEM cooler (like MSI/Asus/whatever) will only get to about 70 - 75'C.

Are you sure everything is as it should be and working correctly with that AIO setup?

Aquinus · Sep 4, 2014

Your 6950 has 2.6 billion transistors where your i5 is half as many, 1.3 billion. The i5 also is built on a smaller process, so one would expect a fully loaded i5 to be less than half the draw of a fully loaded 6950. Also a large portion of GPUs are just bulk shaders, something that is constantly being used by the GPU where there are parts of a CPU that could be left idle for relatively long periods of time.

hat1324 · Sep 4, 2014

Hah makes sense. Slightly off topic, the reason my H55's performance is so mediocre is because my ITX rig pins the radiator centimeters from the graphics card, although removing the ring around the SP120 fan did shave off 5C so thanks for that lol.

doyll · Sep 4, 2014

H55 really isn't designed to handle 200+ watts so it will run hot.

Even H100 can't keep up with top air and sounds 5-7 times as loud trying. Run it at same sound level and it's about 8c hotter then air.

Vario · Sep 4, 2014

hat1324 said:
Hah makes sense. Slightly off topic, the reason my H55's performance is so mediocre is because my ITX rig pins the radiator centimeters from the graphics card, although removing the ring around the SP120 fan did shave off 5C so thanks for that lol.

The ring removed reduced temperatures that much? How is that possible? I didn't know the ring interfered with airflow, does it?

XL-R8R · Sep 4, 2014

I assume it was because he has his rad mounted so close to the back of his card and removing the ring allowed more clearance.

hat1324 · Sep 4, 2014

doyll said:
H55 really isn't designed to handle 200+ watts so it will run hot.

Even H100 can't keep up with top air and sounds 5-7 times as loud trying. Run it at same sound level and it's about 8c hotter then air.

Not even. Lifting the radiator out of its cramped spot gave me 63C max, which was much better than Dual-X would have done given the same clearance. Anyway, I'm only using the H55 because the fans on the Dual-X broke.

System Name	ITX Tower
Processor	Intel i5-4430
Motherboard	ASUS Maximus VI Impact
Memory	8GB HyperX DDR3 1333MHz
Video Card(s)	XFX HD6950
Storage	WD Caviar Black 1TB
Display(s)	Samsung T22B350ND
Case	AZZA CSAZ
Audio Device(s)	SupremeFX Impact
Power Supply	OCZ ZT 750W
Software	Windows 8.1 64-bit

System Name	"IBT 10x Maximum Stable"
Processor	Intel i5 4690K @ 4.6GHz -> 100xx46 - 1.296v
Motherboard	MSI MPower Z97
Cooling	Corsair H100i + 2x Corsair "HP Edition" SP120's
Memory	4x4GB Corsair Vengence Pro 2400mhz @ 2400MHz 10-11-12-31-1T - 1.66v
Video Card(s)	MSI Gaming GTX970 4GB @ 1314 Core/1973 Mem/1515 Boost
Storage	Kingston 3K 120GB SSD + Western Digital 'Green' 2TB + Samsung Spinpoint F3 1TB
Display(s)	Iiyama Prolite X2377HDS 23" IPS
Case	Corsair Carbide 300R
Audio Device(s)	Rotel RA-04/Cambridge Audio Azur 540R + B&W DM302/Cerwin Vega AT12 / Sony MDR-XB700 & FiiO E5
Power Supply	EVGA NEX650G + Silverstone Extensions
Mouse	Always failing me....
Keyboard	Endlessly broken.....
Software	Windoze 7 Pro 64-bit/Windoze 10 Pro
Benchmark Scores	I had some of these once upon a time? Old age has seen me misplace them....

System Name	Apollo
Processor	Intel Core i9 9880H
Motherboard	Some proprietary Apple thing.
Memory	64GB DDR4-2667
Video Card(s)	AMD Radeon Pro 5600M, 8GB HBM2
Storage	1TB Apple NVMe, 4TB External
Display(s)	Laptop @ 3072x1920 + 2x LG 5k Ultrafine TB3 displays
Case	MacBook Pro (16", 2019)
Audio Device(s)	AirPods Pro, Sennheiser HD 380s w/ FIIO Alpen 2, or Logitech 2.1 Speakers
Power Supply	96w Power Adapter
Mouse	Logitech MX Master 3
Keyboard	Logitech G915, GL Clicky
Software	MacOS 12.1

System Name	ITX Tower
Processor	Intel i5-4430
Motherboard	ASUS Maximus VI Impact
Memory	8GB HyperX DDR3 1333MHz
Video Card(s)	XFX HD6950
Storage	WD Caviar Black 1TB
Display(s)	Samsung T22B350ND
Case	AZZA CSAZ
Audio Device(s)	SupremeFX Impact
Power Supply	OCZ ZT 750W
Software	Windows 8.1 64-bit

System Name	Computer of Theseus
Processor	Intel i9-12900KS: 50x Pcore multi @ 1.18Vcore (target 1.275V -100mv offset)
Motherboard	EVGA Z690 Classified
Cooling	Noctua NH-D15S, 2xThermalRight TY-143, 4xNoctua NF-A12x25,3xNF-A12x15, 2xAquacomputer Splitty9Active
Memory	G-Skill Trident Z5 (32GB) DDR5-6000 C36 F5-6000J3636F16GX2-TZ5RK
Video Card(s)	EVGA Geforce 3060 XC Black Gaming 12GB
Storage	1x Samsung 970 Pro 512GB NVMe (OS), 2x Samsung 970 Evo Plus 2TB (data 1 and 2), ASUS BW-16D1HT
Display(s)	Dell S3220DGF 32" 2560x1440 165Hz Primary, Dell P2017H 19.5" 1600x900 Secondary, Ergotron LX arms.
Case	Lian Li O11 Air Mini
Audio Device(s)	Audiotechnica ATR2100X-USB, El Gato Wave XLR Mic Preamp, ATH M50X Headphones, Behringer 302USB Mixer
Power Supply	Super Flower Leadex Platinum SE 1000W 80+ Platinum White
Mouse	Zowie EC3-C
Keyboard	Vortex Multix 87 Winter TKL (Gateron G Pro Yellow)
Software	Win 10 LTSC 21H2

Why do GPUs run hotter than CPUs?

Resident Wat-man