GIR-GVP Port Capacity Tests
Genesys conducted performance tests of various Genesys Interactive Recording (GIR) and GVP Capacities. This section contains test profiles, test results, and analysis.
- GIR-GVP Port Capacity Test Results Summary
- Detailed Studies of GVP Media Server Behavior on Windows
- Detailed Studies of GVP Media Server Behavior on Linux
- Performance Comparison of Physical Server and Virtual Machines
- Performance Comparison of Different Virtual Machines Configurations
- Performance Comparison of MP3 only and MP3 + WAV
- Performance Comparison between SAS HDDs and SSD
- Data Throughput
- MCP IOPS
MP3 16KBPS Bit Rate Compression
Support for MP3 16 kbps bit rate recording compression began with The GVP 8.5.1 release in December 2014. We tested performance on physical server and Virtual Machine (VM) environments, using Windows 2008 R2 x64.
Physical Server on Single Hex Core
Testing was performed on Hardware Profile 1: a physical server on a single hex core of Dell R410. The three graphs below compare system CPU usage and audio quality related metrics, max jitter and max delta.
MP3 16kbps consumes less CPU memory, which means higher port capacity. The two graphs above that compare Max Jitter with Max Delta also indicate the higher port capacity of MP3 16kbps. Recommended port capacity for MP3 16kbps: 240 ports (20% higher than the 200 recommended port capacity for MP3 32kbps). Peak port capacity: 270 ports (22.7% higher than the 220 peak port capacity for MP3 32kbps).
The table below lists the system disk IOPS:
Figure 45: System Disk IOPS on Physical Server, MP3 only 16 Kbps
| Ports | Physical Server Disk IOPS (kbps) | ||
|---|---|---|---|
| Total | Reads | Writes | |
| 60 | 14.66 | 0.036 | 14.62 |
| 120 | 24.00 | 0.041 | 23.95 |
| 180 | 33.42 | 0.029 | 33.39 |
| 210 | 37.65 | 0.030 | 37.62 |
| 240 | 42.21 | 0.029 | 42.18 |
| 270 | 47.18 | 0.036 | 47.14 |
| 300 | 51.44 | 0.011 | 51.43 |
| 330 | 55.81 | 0.006 | 55.81 |
| 360 | 60.99 | 0.002 | 60.99 |
| 390 | 67.12 | 0.003 | 67.11 |
The graph below compares Table: System Disk IOPS on Physical Server, MP3 only 16 Kbps with Table: Disk IOPS of system level from a physical server with a single hex core, both on a single hex core server:
The system disk IOPS for MP3 16kbps and 32kbps are nearly identical to each other; reasonable since the disk IO operations should be the same, and at the same port capacity, no matter which MP3 bit rate is chosen.
MCP IOPS is listed here:
Figure 47: MCP IOPS on physical server of single hex core, MP3 only, 16 Kbps
| Ports | Physical Server MCP IOPS (kbps) | ||
|---|---|---|---|
| Total | Reads | Writes | |
| 60 | 14.56 | 7.53 | 7.04 |
| 120 | 28.64 | 14.92 | 13.72 |
| 180 | 42.54 | 22.29 | 20.25 |
| 210 | 49.42 | 25.93 | 23.48 |
| 240 | 56.41 | 29.64 | 26.76 |
| 270 | 63.38 | 33.34 | 30.04 |
| 300 | 70.36 | 36.92 | 33.44 |
| 330 | 77.53 | 40.79 | 36.74 |
| 360 | 85.52 | 44.46 | 41.06 |
| 390 | 94.68 | 48.14 | 46.54 |
The graph below compares Table: MCP IOPS on physical server of single hex core, MP3 only, 16 Kbps and Table: MCP IOPS on physical server of single hex core, MP3 only:
MP3 16kbps uses less IOPS at the process level, probably be due to fewer network operations for MP3 16kbps.
VMs on Dual Hex Cores Server
The testing for MP3 16kbps was conducted on VM Profile 4 (based on Hardware Profile 4, which is a dual hex cores server). 6 VMs were configured, while only one MCP was installed on each Windows VM. The three graphs below compare overall CPU usage, audio quality related max jitter and max delta for MP3 16kbps vs 32kbps:
MP3 16kbps consumes less CPU memory, which matches test results on a physical server in Figure: Comparison of System CPU Usage, MP3 16kbps vs 32kbps on Physical Server. Both Max Jitter and Max Delta also show a higher port capacity for MP3 16kbps compression, which also matches test results on a physical server from Figure 4: Comparison of Max Jitter, MP3 16kbps vs 32kbps on Physical Server & Figure: Comparison of Max Delta MP3 16kbps vs 32kbps on a Physical Server. Preferred/Recommended port capacity for MP3 16 kbps: 720 ports (20% higher 600 ports for than MP3 32kbps). It’s the same increase as observed from a physical server. Peak port capacity for MP3 16kpbs can be as high as 840 ports (27.3% higher than 660 peak port capacity for MP3 32kbps.
The table below illustrates system disk IOPS:
Figure 52: Overall Disk IOPS on all 6 VMs of dual hex cores, MP3 only, 16 Kbps
| Ports | Overall 6 VMs Disk IOPS (kbps) | ||
|---|---|---|---|
| Total | Reads | Writes | |
| 120 | 26.57 | 0.13 | 26.44 |
| 360 | 63.47 | 0.13 | 63.34 |
| 480 | 80.66 | 0.15 | 80.51 |
| 600 | 93.73 | 0.04 | 93.69 |
| 660 | 109.53 | 0.14 | 109.39 |
| 720 | 118.76 | 0.13 | 118.62 |
| 780 | 126.15 | 0.07 | 126.08 |
| 840 | 134.12 | 0.04 | 134.09 |
| 900 | 142.21 | 0.09 | 142.12 |
The graph below compares overall disk IOPS of all 6 VMs for MP3 16kpbs against 32kbps in Table: Disk IOPS of sum of all 6 VMs of dual hex cores, MP3 only':
The IOPS from both MP3 16kbps and 32kbps are inline with each other, as in the physical server tests.
Data throughput for MP3 16kbps is listed in following table:
Figure 54: Data Throughputs for MP3 only, 16 kbps
| Ports | Overall Disk (kbps) | SSD Drive Disk (kbps) | ||||
|---|---|---|---|---|---|---|
| Total | Reads | Writes | Total | Reads | Writes | |
| 120 | 318.17 | 0.68 | 317.49 | 296.313 | 0.001 | 296.312 |
| 360 | 892.94 | 0.52 | 892.42 | 856.077 | 0.001 | 856.076 |
| 480 | 1175.63 | 0.79 | 1174.84 | 1132.997 | 0.001 | 1132.996 |
| 600 | 1537.43 | 0.19 | 1537.23 | 1510.543 | 0.000 | 1510.543 |
| 660 | 1729.45 | 0.58 | 1728.87 | 1680.374 | 0.003 | 1680.371 |
| 720 | 1890.48 | 0.58 | 1889.90 | 1837.492 | 0.000 | 1837.492 |
| 780 | 2045.34 | 0.35 | 2045.00 | 1995.239 | 0.004 | 1995.235 |
| 840 | 2191.98 | 0.15 | 2191.83 | 2142.373 | 0.002 | 2142.371 |
| 900 | 2349.18 | 0.75 | 2348.44 | 2298.426 | 0.004 | 2298.422 |
Using this formula:
MP3 bitrate * Ports / 8 = kbps
...where MP3 bitrate=16kbps and Ports = 120 and 720 from the table above,
The results...
16 kpbs * 120 / 8 = 240 kbps (compared to 296 in the table -- in SSD)
and
16 kpbs * 720 / 8 = 14400 kbps (compared to 1837 in the table -- in SSD)
...from real testing for MP3 16kbps are slightly higher than calculations predict, due to other files such as metadata and JSON files being saved in the same cache folder. So the formula still stands.
The following table lists MCP IOPS:
Figure 55: Overall MCP IOPS from 6 VMs of dual hex core, MP3 only, 16kbps
| Ports | Overall 6 VMs MCP IOPS (kbps) | ||
|---|---|---|---|
| Total | Reads | Writes | |
| 120 | 28.931 | 14.915 | 14.016 |
| 360 | 86.517 | 44.456 | 42.061 |
| 480 | 114.574 | 59.153 | 55.421 |
| 600 | 142.112 | 73.730 | 68.382 |
| 660 | 156.495 | 81.359 | 75.136 |
| 720 | 170.237 | 88.660 | 81.577 |
| 780 | 184.173 | 96.048 | 88.125 |
| 840 | 197.767 | 103.263 | 94.504 |
| 900 | 211.644 | 110.545 | 101.099 |
The graph below compares Overall MCP IOPS with MP3 32k MCP IOPS, and shows the same trend of physical server results that appeared in Figure: MCP IOPS on Single Hex Core Physical Server, MP3 16Kbps vs 32Kbps:
MP3 16KBPS Bit Rate Compression with Encryption
We tested the MP3 16 kbps bit rate with encryption, using the dest2 physical server and Vitual Machine (VM) environments, which compares with results of non-encryption from MP3 16 kbps Bit Rate without Encryption. The OS remained Windows 2008 R2 x64.
Physical Server on Single Hex Core
These tests were performed on Hardware Profile 1: a physical server on a single hex core of Dell R410. The three graphs below compare system CPU usage and audio quality-related metrics, max jitter and max delta.
In the graphs above, encryption consumes slightly higher system CPU than does non-encryption. Max Jitter and Max Delta consume much more CPU with encryption, than without. If a slightly higher delay due to latency introduced by encryption is acceptable, then recommended and preferred port capacity would be 210 ports—only a 12.5% reduction from the peak capacity of 240 ports offered by non-encryption. If the audio quality strictly applies, then the recommended port capacity can be as low as 120 ports. Peak port capacity could be the same 270 ports as non-encryption, if the delay is acceptable.
The table below lists system disk IOPS:
Figure 60: IOPS on physical server of single hex core, MP3 only, 16 Kbps, encryption
| Ports | Physical Server Disk IOPS | ||
|---|---|---|---|
| Total | Reads | Writes | |
| 60 | 14.66 | 0.036 | 14.62 |
| 120 | 24.00 | 0.041 | 23.95 |
| 180 | 33.42 | 0.029 | 33.39 |
| 210 | 37.65 | 0.030 | 37.62 |
| 240 | 42.21 | 0.029 | 42.18 |
| 270 | 47.18 | 0.036 | 47.14 |
| 300 | 51.44 | 0.011 | 51.43 |
| 330 | 55.81 | 0.006 | 55.81 |
| 360 | 60.99 | 0.002 | 60.99 |
| 390 | 67.12 | 0.003 | 67.11 |
The graph below compares system disk IOPS on a physical server IOPS with non-encryption:
System disk IOPS is nearly the same for encryption and non-encryption; both increase slightly at a higher port capacity. Some of that can be attributed by other disk IO operations, such as encryption key files.
The table below lists MCP IOPS:
Figure 62: MCP IOPS on physical server of single hex core, MP3 only, 16 Kbps, encryption
| Ports | Physical Server MCP IOPS | ||
|---|---|---|---|
| Total | Reads | Writes | |
| 60 | 16.53 | 8.88 | 7.65 |
| 120 | 32.59 | 17.69 | 14.91 |
| 150 | 40.40 | 21.96 | 18.44 |
| 180 | 48.46 | 26.46 | 22.01 |
| 210 | 56.35 | 30.83 | 25.52 |
| 240 | 64.32 | 35.24 | 29.08 |
| 270 | 72.28 | 39.64 | 32.64 |
| 300 | 80.06 | 43.95 | 36.11 |
| 330 | 88.61 | 48.53 | 40.07 |
| 360 | 100.48 | 52.91 | 47.57 |
The graph below compares total MCP IOPS between encryption and non-encryption:
MCP IOPS for encryption increases when port capacity increases. As seen in Figure: Comparison of System Disk IOPS on Single Hex Core Physical Server, MP3 16kbps encryption vs non-encryption, increase for disk IOPS is much smaller for encryption, so here the increase should be attributed to network IOs.
VMs on Dual Hex Cores Server
The testing for MP3 16kbps with encryption was conducted on the VM Profile 4 based on Hardware Profile 4 of a dual hex cores server, same as non-encryption in the 16knps tests VMs on Dual Hex Cores Server. Six VMs were configured while only one MCP was installed on each Windows VM. Below are three graphs comparing overall CPU usage, audio quality related max jitter and max delta for MP3 16kbps encryption vs non-encryption:
The VM environment exhibits a similar trend: slightly overall CPU usage for the encryption profile, and much higher for max jitter and max delta. Applying the same criteria from the physical server results, if a slightly higher delay (due to latency introduced by encryption) is acceptable, then the recommended and preferred port capacity could be 600 ports—only a 16.7% reduction of the peak 720 ports with non-encryption. If audio quality strictly applies, the recommended ports can be as low as 480 ports. And if some delay is acceptable, then the peak port capacity can be the same 840 ports as non-encryption.
The overall system disk IOPS for all 6 VMs is listed below:
Figure 67: Overall Disk IOPS on all 6 VMs of dual hex cores, MP3 only, 16 Kbps, encryption
| Ports | Overall 6 VMs Disk IOPS | SSD Drive Disk IOPS | ||||
|---|---|---|---|---|---|---|
| Total | Reads | Writes | Total | Reads | Writes | |
| 120 | 28.70 | 0.004 | 28.69 | 21.881 | 0.000 | 21.881 |
| 360 | 67.46 | 0.004 | 67.46 | 56.238 | 0.000 | 56.238 |
| 480 | 87.56 | 0.026 | 87.54 | 74.903 | 0.000 | 74.903 |
| 600 | 108.01 | 0.015 | 107.99 | 93.647 | 0.000 | 93.647 |
| 660 | 119.49 | 0.005 | 119.48 | 104.304 | 0.000 | 104.304 |
| 720 | 128.76 | 0.020 | 128.74 | 114.441 | 0.000 | 114.441 |
| 780 | 137.68 | 0.015 | 137.66 | 123.210 | 0.002 | 123.209 |
| 840 | 146.99 | 0.009 | 146.98 | 132.646 | 0.002 | 132.644 |
| 900 | 154.68 | 0.025 | 154.66 | 140.145 | 0.002 | 140.143 |
The graph below compares system disk IOPS with encryption and with non-encryption, on the same VM environment:
As with the physical server tests, encryption increases as port capacity increases. Also as with the physical server tests, some of that can be attributed to extra disk IO operations.
The table below lists Data throughputs for encryption:
Figure 69: Data Throughputs for MP3 only, 16 kbps, encryption
| Ports | Overall Disk KB/sec | SSD Drive Disk KB/sec | ||||
|---|---|---|---|---|---|---|
| Total | Reads | Writes | Total | Reads | Writes | |
| 120 | 387.99 | 0.02 | 387.97 | 304.229 | 0.000 | 304.229 |
| 360 | 1096.82 | 22.54 | 1074.28 | 876.599 | 0.000 | 876.599 |
| 480 | 1344.60 | 107.95 | 1236.65 | 1191.403 | 0.006 | 1191.397 |
| 600 | 2187.50 | 348.40 | 1839.09 | 1532.171 | 0.000 | 1532.171 |
| 660 | 2024.16 | 35.09 | 1989.07 | 1652.232 | 0.000 | 1652.232 |
| 720 | 1955.33 | 99.81 | 1855.51 | 1803.207 | 0.006 | 1803.201 |
| 780 | 2572.79 | 205.15 | 2367.64 | 1982.733 | 0.024 | 1982.709 |
| 840 | 2534.97 | 28.65 | 2506.32 | 2097.871 | 0.043 | 2097.829 |
| 900 | 2851.85 | 119.47 | 2732.38 | 2297.264 | 0.007 | 2297.257 |
Using Formula 1...
MP3 bitrate * Ports / 8 = KB/sec
Or 16kbps * Ports / 8 =KB/sec if MP3 is 16kbps
...take two samples (120 & 720) from the above table above, and apply them to Formula 1:
16 kpbs * 120 / 8 = 240 kb close to 304 in the table (in SSD)
16 kpbs * 720 / 8 = 14400 kb close to 1803 in the table (in SSD)
The measurements from real testing for MP3 16kbps encryption are slightly higher than these calculations predict, due to other file, such as metadata and JSON files, being saved on the same cache folder.
The graph below compares overall data throughputs with no encryption:
The data throughputs for encryption increase slightly when port capacity increases, matching a similar trend with system disk IOPS.
The table below lists overall MCP IOPS from all 6 VMs:
Figure 71: Overall MCP IOPS from 6 VMs of dual hex core, MP3 only, 16kbps, encryption
| Ports | Overall 6 VMs MCP IOPS | ||
|---|---|---|---|
| Total | Reads | Writes | |
| 120 | 34.874 | 17.638 | 17.236 |
| 360 | 102.624 | 52.900 | 49.724 |
| 480 | 130.285 | 70.377 | 59.909 |
| 600 | 168.849 | 87.766 | 81.083 |
| 660 | 186.175 | 96.882 | 89.293 |
| 720 | 193.248 | 105.171 | 88.077 |
| 780 | 219.395 | 114.398 | 104.997 |
| 840 | 235.730 | 123.009 | 112.720 |
| 900 | 252.198 | 131.682 | 120.516 |
The graph below compares performance of the same configuration, except with non-encryption:
MCP IOPS performance is affected slightly by encryption, similar to the trend expressed in the physical server results.