Article ID: V1-15-01-20-t
Released Date: 01/20/2015
Applied to
GV-VMS V14.10
Summary
The document consists of three sections:
- The total frame rate and the number of channels GV-VMS can support based on different CPU types, codec and resolutions
- Workarounds to increase total frame rates supported by GV-VMS
- The total frame rate supported by a single hard disk
1. Total Frame Rate and Number of Channels Supported
The tables below show the total frame rates and number of channels GV-VMS can support with CPU usage under approximately 70% to ensure performance and stability. The test results vary according to the CPU types (Core i7, Core i5 and Core i3), the resolution and compression method (codec) set on the connected IP camera.
Also shown in the table is the number of full-frame channels GV-VMS can support. Note that the maximum number of frames per channel differs at different resolutions. Full-frame at 1.3 ~ 5 MP resolutions are defined as follows:
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Single Stream vs Dual Streams
When IP devices are set to dual streams, the total frame rate supported is increased because you can select lower resolution for live view and set the other stream to high quality video for recording. CPU usage is affected by live view decoding not recording.
CPU Decoding vs GPU Decoding
If your IP device does not support dual streams, refer to tables 3 to 5 for test results of single stream with CPU and GPU decoding. A higher total frame rate can be achieved if your CPU supports GPU decoding.
Note that GPU decoding only supports H.264 codec and that different chipsets have different resolution limitations:
- Intel Sandy Bridge Chipsets only support GPU decoding of 1.3 MP to 2 MP videos
- Intel Ivy Bridge and Haswell Chipsets support GPU decoding of 1.3 MP to 5 MP videos
When using GPU decoding, higher RAM can increase the total frame rate supported. Refer to tables 3 and 4 to see the GPU decoding test results for 4 GB RAM versus 8 GB RAM. When using CPU decoding and single stream, however, the total frame rate supported is usually limited by CPU loading, and not affected by RAM (see table 5).
Note: The test results below were obtained using a panel resolution of 1920 x 1080. The results may vary based on various factors, including actual environment and bitrates.
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1.1 Test Environment
The total frame rate and number of full-frame channels supported based on CPU usage were obtained using the following bitrate and test PC.
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2. Workarounds to Increase Total Frame Rates
If your CPU capacity is lower than Core i7, Core i5 or Core i3 but wish to reach high frame rates, you can use dual streams or sacrifice the resolution as a workaround.
2.1 Using Dual Streams
If you are unable to reach the desired frame rate, it is highly suggested to use the dual-stream function if available on your IP device.
GeoVision IP Cameras feature dual streams, capable of delivering two video streams in different resolution, codec and frame rate. Using dual streams, you can lower the resolution and codec for live images, but set the recording stream to mega pixel resolution for high quality recording and to H.264 codec for small file size.
Here we use GV-BX320D as an example. You can set Stream 1 and Stream 2 to different resolutions.
- Stream 1 (recording) settings: Select 2048 x 1536 (3 MP) resolution for the best recording quality, and select H.264 codec for the smallest file size.
- Stream 2 (live view) settings: Select either 640 x 480 (VGA) or 320 x 240 (CIF) resolution depending on your CPU capacity. Higher resolution requires more CPU resource.
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If your IP device does not support the dual-stream function, you may consider decreasing the image resolution. Decreasing the image resolution can reduce CPU usage and allows the GV-VMS to achieve higher frame rates.
3. Hard Disk Limitations
The hard disk performance can greatly affect GV-VMS’s performance. When the size of transmitted data is large and exceeds the transfer rate of a hard disk, you may encounter problems such as time gaps, frame dropping and high hard disk failure rate . To avoid these problems and have the maximum performance out of GV-VMS, you should note the total recording frame rate that you can assign to a single hard disk, as listed below:
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The frame rate limit is based on the resolution and codec of video sources. The higher video resolution, the lower frame rate you can assign to a single hard disk. In other words, the higher frame rate you wish to record, the more hard disks you need to install on your system.
For example, if you want to connect 64 units of GV-FD5300 and record at 5 megapixel resolution, you will need at least 4 hard disks. The calculation and hard disk assignments are given below
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Note: It is highly recommended to use separate hard disks for installing Windows operating system and for storing recorded files.
3.1 Test Environment for Hard Disk Limitations
Note: The Hard Disk Limitations were obtained using the bitrate listed above and hard disk below: WD Caviar Black, WD1002FAEX (SATA 6 GB/s), 64 MB cache.
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