Nominal resistance on power rails of various PC hardware

During repair of broken PC hardware it’s usually pretty accurate way to determine if complex ASIC like graphics processor or CPU damaged by overvoltage or overheat by simple measurement of power node resistance.

To do so you will need to remove power inductors between chip and DC-DC VRM (those are usually row of big inductors, featuring multi-phase convertor) and measure resistance to ground on output node (chip side) using usual DMM in resistance measurement mode. You should get value in range of few ohms, depends on specific GPU.

Here’s collected data based on actual measurements of some operational hardware:

Graphic card GPU ID GPU, Ω DRAM, Ω Vio,V Vgpu 2D Vgpu 3D Vmem
NVIDIA GeForce 2 MX400 200
NVIDIA GeForce 4 MX440-8x 13-23
NVIDIA GeForce 4 Ti 4400 12 138
NVIDIA GeForce 4 Ti 4600 10.8 137
NVIDIA GeForce 4 Ti4200 20
NVIDIA GeForce 4 Ti4200-8x 19
NVIDIA GeForce 5900 XT NV35 5,7-6 194
NVIDIA GeForce 5950 Ultra 3.8-4.2 108
NVIDIA GeForce 6600 2-5
NVIDIA GeForce 6600 AGP 7.3
NVIDIA GeForce 6600 PCI-E 4.5
NVIDIA GeForce 6600GT 2.2-2.6
NVIDIA GeForce 6600GT AGP 3.2 15.2 1.4 2
NVIDIA GeForce 6600LE 5.1 130 1,3 2,2
NVIDIA GeForce 6800 2.2
NVIDIA GeForce 7600 7,6
NVIDIA GeForce 7600GS AGP 2.8 55 17 1.23 2.1
NVIDIA GeForce 7600GT 4,4 71,3
NVIDIA GeForce 7800GT OC 3.5 50.5 1.25 2
NVIDIA GeForce 7800GT PCI-E 1.7 45 1.3 2.1
NVIDIA GeForce 7800GTX 3.1 56 1.25 1.5 2.1
NVIDIA GeForce 7900GS 1,37 27
NVIDIA GeForce 7900GTO G71 2.6 31
NVIDIA GeForce 7900GTX 2 25,6
NVIDIA GeForce 7950GT G71 2.3 101.7
NVIDIA GeForce 7950GT AGP G71 1.7 30 1.3 2
NVIDIA GeForce 7950GX2 top 2,25 33
NVIDIA GeForce 8600 GT 6-8 105 1.4 2.1
NVIDIA GeForce 8600 GTS 512 2.4 44.5 1.44 2.15
NVIDIA GeForce 8800 GT G92 1 63 1.12 2.1
NVIDIA GeForce 8800 GTS G92 1 61 1.18 2
NVIDIA GeForce 8800 GTS G80 1 28.5 1.27 1.9
NVIDIA GeForce 8800 GTS G80 0.7-1
NVIDIA GeForce 9600GT G94 1 55 1.2 2
NVIDIA GeForce FX 5200 7
NVIDIA GeForce FX 5200 10.5
NVIDIA GeForce FX 5600 17
NVIDIA GeForce FX 5900 XT 5 1.2 1.4 2.73
NVIDIA Quadro4 980 XGL 9.11 133
ATI Radeon 9800Pro 15
ATI Radeon 2600XT DDR3 512MB 3.25 32.2
ATI Radeon 2900XT 0.42 8.45 57
ATI Radeon 7500 64
ATI Radeon 9100 35
ATI Radeon 9200LE 64MB 335 1.6 2.7
ATI Radeon 9600 8
ATI Radeon 9600XT 5
ATI Radeon 9700 Pro 8
ATI Radeon 9800SE 10
ATI Radeon HD 4850 1 16 1.1 2.1
ATI Radeon X1300 AGP 10.3 77.4
ATI Radeon X1650 PCI-E 2.9 86.2
ATI Radeon X1900GT 1.9 17.3
ATI Radeon X1950GT 1
ATI Radeon X300 SE 128MB 64b 4.44
ATI Radeon X550 PCI-E 5.2-10
ATI Radeon X800 17.9
ATI Radeon X800GTO 3-5 14-17
ATI Radeon X800XL 4

Also here are some newer card useful reference points, key resistance values measured with high-accuracy Keithley 2002 DMM on good working card:

GPU Voltage rail Resistance measured Nominal voltage
1080 NVVDD 80-250 milliΩ 0.64 VDC … 1.1VDC
FBVDD ~97 Ω 1.35 VDC fixed
PEX ~44 Ω 1.02 VDC fixed
MEMPLL ~450 Ω 1.80 VDC fixed
1080 Ti/Titan Xp NVVDD 40-180 milliΩ 0.64 VDC … 1.1VDC
FBVDD ~80 Ω 1.35 VDC fixed
PEX ~80 Ω 1.02 VDC fixed
MEMPLL ~460 Ω 1.80 VDC fixed
980 Ti NVVDD ~1.5-5 Ω 0.7 VDC … 1.21VDC
FBVDD ~15 Ω 1.50 VDC fixed
PEX ~200 Ω 1.02 VDC fixed
980 NVVDD ~3.5-8 Ω 0.7 VDC … 1.21VDC
FBVDD ~30 Ω 1.50 VDC fixed
PEX ~180 Ω 1.02 VDC fixed
780 Ti NVVDD ~1.5-4 Ω 0.8 VDC … 1.23VDC
FBVDD ~55 Ω 1.50 VDC fixed
PEX ~160 Ω 1.02 VDC fixed

Table 2: Nominal resistance on main power rails from good GeForce GTX cards

Author: xDevs.com Team
Published: Sept. 10, 2009, 9:03 a.m.
Modified: Sept. 19, 2017, 11 a.m.

References

If you would like to support us by making a donation please click the Paypal button:

Comments