According to the Ubuntu OS information, out of a total of 16GB of memory available on this board, 10.0 GiB (10.74 GB) is the actual amount available for use by the operating system and new programs.
root@orangepi6:/# free -h
total used free shared buff/cache available
Mem: 15Gi 4.9Gi 7.3Gi 110Mi 3.5Gi 10Gi
Swap: 0B 0B 0B
Memory Category
Capacity / Usage
Percentage of Total
System Function & Details
Total Memory
15.0 GiB
100%
Total physical LPDDR RAM recognized by the system.
Available
10.0 GiB
~66.7%
RAM is immediately ready for allocation to new apps without swapping.
Free
7.3 GiB
~48.7%
Completely unallocated and idle memory space.
Used
4.9 GiB
~32.7%
Memory is actively consumed by processes and OS core components.
Buff / Cache
3.5 GiB
~23.3%
Data cached in RAM by the kernel to speed up storage read/write I/O.
Virtual memory on disk (currently disabled / not configured).
The difference lies between unassigned memory and usable memory:
Free (7.3 GiB) represents raw, completely untouched memory. The system is doing absolute zero work with this space—it sits completely idle.
Available (10.0 GiB) represents how much total memory can actually be given to a new or existing app without forcing the system to dump data to disk or crash.
Sysbench Memory Benchmark Comparison
Board
RAM
Sysbench Memory Write Throughput
Orange Pi 6 Plus(32GB)
LPDDR5
4174 MiB/sec
Orange Pi 6 (16GB)
LPDDR5
4,424.50 MiB/sec
Raspberry Pi 5 (16GB)
16GB LPDDR4X
~6500–7000 MiB/sec
root@orangepi6plus:/# sudo apt install sysbench
sysbench memory --memory-block-size=1KiB --memory-total-size=102400MiB --memory-oper=write --memory-scope=global --threads=1 run
sysbench memory run
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
sysbench is already the newest version (1.0.20+ds-5).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
sysbench 1.0.20 (using system LuaJIT 2.1.0-beta3)
Running the test with following options:
Number of threads: 1
Initializing random number generator from current time
Running memory speed test with the following options:
block size: 1KiB
total size: 102400MiB
operation: write
scope: global
Initializing worker threads...
Threads started!
Total operations: 42774901 (4274957.60 per second)
41772.36 MiB transferred (4174.76 MiB/sec)
Geekbench benchmarking
#Installing Geekbench 7.0 - Linux/AArch64 (Preview Edition)
wget https://cdn.geekbench.com/Geekbench-7.0.0-LinuxARMPreview.tar.gz
tar -xf Geekbench-7.0.0-LinuxARMPreview.tar.gz
cd Geekbench-7.0.0-LinuxARMPreview
./geekbench7
📊 Geekbench 6.5.0 Results — Orange Pi 6 Board (16GB)
Overall Scores
Performance Metric
Score
Single-Core Score
1167
Multi-Core Score
6798
Comparing results to the Orange Pi 6 (32GB) and Raspberry Pi 5 (16GB)
Performance Difference relative to the Raspberry Pi 5
Using the Geekbench 7 figures from the comparison chart:
Single-Core Speed:
vs. Orange Pi 6 (16GB): The Raspberry Pi 5 (796) is 31.8% slower than the Orange Pi 6 (1167). The Orange Pi 6 delivers 1.47× the single-threaded performance.
vs. Orange Pi 6 Plus (32GB): The Raspberry Pi 5 is 38.3% slower than the Orange Pi 6 Plus (1291). The Orange Pi 6 Plus delivers 1.62× the single-threaded performance.
Multi-Core Speed:
vs. Orange Pi 6 Plus (32GB): The Raspberry Pi 5 (1584) is 75.9% slower than the Orange Pi 6 Plus (6568). The Orange Pi 6 Plus delivers 4.15× the total multi-threaded throughput.
vs. Orange Pi 6 (16GB): The Raspberry Pi 5 is 76.7% slower than the standard Orange Pi 6 (6798). The Orange Pi 6 delivers 4.29× the total multi-threaded throughput.
Single-Core Performance Details
Benchmark
Score
Measured Metric
PDF Viewer
1515
68.0 Mpixels/sec
Navigation
1449
7.98 routes/sec
File Compression
1427
203.1 MB/sec
HTML5 Browser
1427
17.8 pages/sec
Structure from Motion
1342
24.3 Kpixels/sec
Text Processing
1234
72.8 pages/sec
Audio Encoder
1153
1.60 Msamples/sec
Ray Tracer
1152
323.6 Ksamples/sec
Asset Compression
1155
25.7 MB/sec
Photo Library
1150
3.94 images/sec
Clang
1142
6.18 Klines/sec
Game Physics
1084
43.8 FPS
Video Encoder
1089
39.6 FPS
Video Player
994
105.1 FPS
HDR
1029
62.2 Mpixels/sec
Photo Editor
654
12.0 images/sec
Multi-Core Performance Details
Benchmark
Score
Measured Metric
Asset Compression
9161
203.5 MB/sec
Ray Tracer
8914
2.50 Msamples/sec
Photo Library
7985
27.4 images/sec
Clang
7651
41.4 Klines/sec
File Compression
6263
891.1 MB/sec
Text Processing
5799
342.1 pages/sec
HDR
5138
310.4 Mpixels/sec
Photo Editor
4900
90.0 images/sec
Sub-Test
Orange Pi 6 (12 cores, 16GB) [Geekbench 7.0 Preview]
Raspberry Pi 5 (4 cores, 16GB) [Geekbench 6.3.0 Preview]