RAM speed test online. Bandwidth and latency, measured.
Measure how fast your memory moves data and how long a trip to it takes, from this browser. Part of the free run, with nothing to install.
One thread
Six threads
Illustrative figures. Not a measurement.
Bandwidth
One thread and all
Latency
Cache and main memory
Run
Inside the 3 minute test
Reports
Read, write, latency
Memory speed, apart from processor speed.
A machine can have a fast processor and still feel slow while it waits on memory. The memory stage measures that separately, so the two are not confused.
- Read and write bandwidth
- How many gigabytes per second the page can read and write, first from one thread and then from every thread at once.
- One thread against all
- Comparing the two shows how well memory keeps up when every core wants it at the same time, which is when a slow memory setup shows.
- Round-trip latency
- The time to reach data in the processor's cache and in main memory, measured on the same machine so their ratio means something.
- Reported, not scored
- There is no fair scale yet for what a given bandwidth means for every class of machine, so the figures are shown as measured and do not change your score.
What a RAM speed test can and cannot tell you.
Bandwidth and latency describe how quickly memory serves the processor. They do not test memory for errors.
Bandwidth
Higher is faster. Dual-channel memory and faster modules raise it; a single module or memory shared with integrated graphics lowers it.
Latency
Lower is faster. The gap between cache and main memory is normal; what matters is how your machine compares with itself across runs.
Installed memory
Where the browser shares it, the report shows roughly how much memory is installed. Chrome reports at most 8 GB, so 8 means 8 GB or more.
Not an error test
Faulty memory needs a tool such as MemTest86 or Windows Memory Diagnostic, which test every cell. A browser cannot do that.
One thread
Six threads
Illustrative figures. Not a measurement.
Hardware
What it needs. Three tiers, no fine print.
Minimum
Any recent browser
The stage runs in Chrome, Edge, Firefox and Safari.
Recommended
Other apps closed
Busy memory from other apps lowers bandwidth, so close heavy apps before the run.
Optimal
Compare two runs
Run before and after a memory upgrade to see the change on your own machine.
In short
RAM speed test: the answer first
A RAM speed test in the browser measures how many gigabytes per second the page can read and write, from one thread and then from every thread, and how long a trip to cache and to main memory takes. The figures are shown as measured and are not folded into a score.
Reading your result
- One thread against all threads
- If all-thread bandwidth is not much higher than one-thread bandwidth, memory is the shared limit when every core wants it, which is common with a single module or memory shared with integrated graphics.
- Latency is a ratio, not a grade
- The gap between cache and main memory is normal on every machine. Compare your own runs before and after a change, such as adding a second module.
- Speed is not health
- Fast figures do not prove the memory is free of errors. MemTest86 or Windows Memory Diagnostic test every cell; a browser cannot.
What good looks like
The ranges, before you run it.
Installed memory
- 16 GB or more
- Comfortable
- Many apps and tabs open at once.
- 8 GB
- Fine, can be tight
- Everyday work; many tabs or big apps fill it.
- Under 8 GB
- Limited
- Slows down when several apps are open.
What a browser cannot see
The honest limits, and where to look instead.
- How full your memory isA web page cannot see how much memory is in use. If the machine slows down with many apps or tabs open, check it directly.
- On a MacActivity Monitor, Memory tab: Memory Pressure at the bottom. Yellow or red means memory is the limit.On WindowsTask Manager (Ctrl+Shift+Esc), Performance, Memory. Above about 85% in use while you work means memory is the limit.
- Temperatures and fan speedNo browser can read a temperature sensor, so heat shows here only as speed lost over time.
- On a MacA free app such as Stats shows temperatures and fan speed.On WindowsHWiNFO, or your laptop maker's own app.
- Storage speed and healthOpening apps and files depends on the drive, which this test does not touch.
- On a MacDisk Utility, then First Aid on your main drive.On WindowsCrystalDiskInfo shows the drive's health status.
Questions
RAM speed test, answered
- Can I test my RAM speed online?
- Yes. The memory stage measures read and write bandwidth and latency from the browser, with nothing to install. It measures speed, not errors.
- Does an online RAM test check for faulty memory?
- No. Finding faulty memory means writing and checking every cell, which needs MemTest86 or Windows Memory Diagnostic. This test measures how fast memory serves the processor.
- Why does it say 8 GB when I have 16 GB?
- Chrome deliberately reports installed memory as at most 8 GB for privacy, so 8 means 8 GB or more. Safari and Firefox do not report it at all.
- Can it see how full my memory is?
- No. A web page cannot see memory in use. The section below says where to check it on Windows and on a Mac.
- Will more RAM make the result faster?
- Not by itself. Bandwidth depends mostly on memory speed and on running two modules in dual channel. More memory helps when the machine runs out, which this test cannot see.
- Will dual-channel memory show up in this test?
- It shows as higher all-thread bandwidth. Run once with your current setup and again after the change; the before and after on the same machine is the honest comparison.