GPU-Z numeric PerfCap reasons?

[dononelson]

Hi all, newbie to this forum here. I recently started using gpu-z, and decided to log the results to a file. After importing the log into Excel, I found that the PerfCap reasons were numeric. Can anyone translate what reason "0" (zero) is? I know that 16 is probably "Util", but during a session of Crysis 3, it changed to zero. During that time, GPU load was 99%.

Any help is much appreciated.

 

[W1zzard]

    /*!
     * Power. Indicating perf is limited by total power limit.
     */
    NV_GPU_PERF_POLICY_ID_SW_POWER = 1,
    /*!
     * Thermal. Indicating perf is limited by temperature limit.
     */
    NV_GPU_PERF_POLICY_ID_SW_THERMAL = 2,
    /*!
     * Reliability. Indicating perf is limited by reliability voltage.
     */
    NV_GPU_PERF_POLICY_ID_SW_RELIABILITY = 4,
    /*!
     * Operating. Indicating perf is limited by max operating voltage.
     */
    NV_GPU_PERF_POLICY_ID_SW_OPERATING = 8,
    /*!
     * Utilization. Indicating perf is limited by GPU utilization.
     */
    NV_GPU_PERF_POLICY_ID_SW_UTILIZATION = 16,
    /*!
     * SLI GPUBoost Synchronization.
     */
    NV_GPU_PERF_POLICY_ID_SW_SLI_GPU_BOOST_SYNC = 32,

The value can be a combination of two or more flags, in which case they get added (technically OR'd). E.g.: 18 would be SW_THERMAL + SW_UTILIZATION (2 + 16)

 

[dononelson]

hmmm, then I wonder what zero is? This is a GEForce 660M. Here is a snippet of the log:

 

[W1zzard]

Zero means no perfcap active

 

[dononelson]

That's interesting - when the card is idle, it has a PerfCap of 16 (Utilization), but when GPU load is 99%, it has no PerfCap active...

 

[FYFI13]

when the card is idle, it has a PerfCap of 16 (Utilization)

Performance is limited (capped) due to very low utilization (load).

when GPU load is 99%, it has no PerfCap active...

The card is working on full power, hence it's performance is not capped. Also it means that card is not overheating, no being over-volted and so on.