86
votes
Why is my HDD so slow on the "4K" speed tests?
What you are running into is typical of mechanical HDDs, and one of the major benefits of SSDs: HDDs have terrible random access performance.
In CrystalDiskMark, "Seq" means sequential access while "...
- 61.7k
53
votes
How can I produce high CPU load on a Linux server?
One alternative way would be
openssl speed -multi $(grep -ci processor /proc/cpuinfo)
or (if nproc is present)
openssl speed -multi $(nproc --all)
OpenSSL is almost always present on nowadays ...
- 694
50
votes
Why does a server CPU perform faster tasks than a Macbook Pro CPU with the same benchmark score?
Benchmarks are vague handwaves to some very specific performance characteristics (peak instruction rate) that often do not take into account other factors in a system.
A non-exhaustive list of ...
- 92.7k
17
votes
Accepted
Why are 4k reads in hdd/ssd benchmarks slower than writes?
TL;DR: It is because the SSD is lying to you and saying the write is done before it is. It can't get away with the same thing for reads.
The longer version of the answer is write caching.
Lets ...
- 6,747
11
votes
Accepted
Why is moving files between btrfs subvolumes an expensive operation?
How is that different subvolumes can share data blocks when using COW, but not in the should-be easier operation of moving data?
mv uses the rename syscall to attempt the move. btrfs's kernel rename ...
- 226
10
votes
SSD with write cache buffer flushing turned on is way slower in AS SSD but not CDM
Usually data losses may only be possible in cases of faulty hardware or unclean shutdowns (sudden power outages, heat protection kick-ins, BSODs, etc.). But many programs are aware of that (all ...
- 2,003
10
votes
How to test router-to-PC connection speed?
If you have two available computers, you can measure the TCP speed directly
between them, without using file-transfer which is notoriously slow.
The tool to use is iPerf, available for all major ...
- 481k
10
votes
Why does a server CPU perform faster tasks than a Macbook Pro CPU with the same benchmark score?
Adding to Mokubai's excellent answer:
Instruction Set Extensions. Some extensions, such as AVX-512, are available in server processors (such as the SKX processor mentioned in the question) but not (...
- 558
7
votes
Accepted
What are the differences between a physical and virtual RAM disk?
Assigning physical memory will yield more consistent and faster results. Anything 'virtual' will be slower as per the experience shared at http://www.tomshardware.com/answers/id-2047362/windows-...
- 9,623
7
votes
Why does a server CPU perform faster tasks than a Macbook Pro CPU with the same benchmark score?
Intel Xeon Platinum 8151 Specs From Intel Corporation
Intel i5-8259U Specs From Intel Corporation
It appears the Xeon has 38.5 MB L3 Cache
It appears the Intel Core i5-8259U has only has 6 MB Intel® ...
4
votes
Fastest Linux Filesystem on Shingled Disks
If you rsync from an SMR drive, make sure that filesystem is mounted read-only or with noatime option.
Otherwise the SMR drive will need to write a timestamp for each file rsync reads, resulting in a ...
- 51
4
votes
Accepted
Why does a server CPU perform faster tasks than a Macbook Pro CPU with the same benchmark score?
Given the task you describe, compiling a Bable project, and the CPUs involved I think I know the source of the difference in performance. I wanted to answer earlier but had to do a bit of research to ...
- 712
3
votes
Why is my HDD so slow on the "4K" speed tests?
As already pointed out by other answers, "4K" almost certainly refers to random access in blocks of size 4 KiB.
Every time a hard disk (not a SSD) is asked to read or write data, there are two ...
- 29.9k
3
votes
SSD with write cache buffer flushing turned on is way slower in AS SSD but not CDM
It seems to me by Occam's Razor, if AS SSD has bad results
when buffer flushing is on, then this reflects the fact that
data takes longer to be written to the disk.
The measuring by AS SSD seems to go ...
- 481k
3
votes
how to find out the actual hardware configuration of my PC in software level?
Quick and dirty: Start > Run > MSINFO32.exe
Now if you mean that the hardware ID is somehow being spoofed to Windows and doesn't report correctly either... you've really got problems big enough to ...
- 51
2
votes
How can I produce high CPU load on a Linux server?
I combined both +jlliagre and +ecabuk.
#!/bin/bash
lc() {
nowMs=$(date +%s)
(
pids=""
cpus=${1:-1}
seconds=${2:-60}
echo "[$(date)] loading $cpus CPUs for $...
- 193
2
votes
How can I produce high CPU load on a Linux server?
Here's the way I use and there's no need to install anything extra.
For example to start with 4 processes,
nproc | xargs seq | xargs -n1 -P4 md5sum /dev/zero
You can change the number of processes ...
- 21
2
votes
Accepted
Very slow random read of SSD on desktop (9,000 IOPS) but normal on laptop
The fact that the 4K random speeds did not increase as much as expected when the queue depth is increased to 32 probably means that NCQ is not in effect.
Usually that's because SATA mode is not AHCI ...
- 9,643
2
votes
Accepted
Is my HDD about to die ? (Erratic benchmark results)
It's a good thing that you've tested the HDD with our tool and since it's saying that the drive is healthy.
However, I've noticed a couple of bad sectors detected (the C5 - Current Pending Sectors ...
- 536
2
votes
Accepted
How to compare 2 specific processors with the same benchmark side by side?
The Passmark comparison site should do the trick.
- 84
2
votes
Why is my HDD so slow on the "4K" speed tests?
4K refers to random I/O. This means the disk is being asked to access small blocks (4 KB in size) at random points within the test file. This is a weakness of hard drives; the ability to access data ...
- 46.1k
2
votes
Why does a server CPU perform faster tasks than a Macbook Pro CPU with the same benchmark score?
In addition to the other answers, I would add that instructions used in any given benchmark may not match the instructions used in your compiler. Basically, each processor may be faster at certain ...
- 248
2
votes
Why does a server CPU perform faster tasks than a Macbook Pro CPU with the same benchmark score?
You just invented one more benchmark - "building this particular project". And the build environment in Amazon is way better than your Mac AT THIS PARTICULAR BENCHMARK.
CPUs (and storage devices, and ...
- 1,222
2
votes
Accepted
is there a method to benchmark only the filters in an ffmpeg chain, ignoring the encoder operations?
It would be
ffmpeg -i input `bench@pre=start,filter1,filter2,filter3,bench@post=stop` -f null -
The first bench filter starts the clock. The 2nd measures stop time and prints it per-frame, along with ...
- 36.4k
2
votes
How can PC's be bottlenecked by GPUs if they have gotten so much faster than CPUs over the last 5 years?
The system could still be bottlenecked by the GPU if the load uses the GPU more than the CPU. What causes the bottleneck in the system depends on the use case. Games tend to be more GPU bound than ...
- 390
2
votes
Accepted
How can PC's be bottlenecked by GPUs if they have gotten so much faster than CPUs over the last 5 years?
I agree with @theJack answer - but would like to expand on it and re-emphasise the relative importance of CPU and GPU is very load-type specific. A system which will be doing a lot of compiling of ...
- 70.8k
2
votes
Accepted
Expected results of a stream memory bandwidth benchmark
TL;DR
Your STREAM benchmark results look alright, but careful interpretation is needed to reach the correct conclusion. In your particular case (and it's usually the case whenever GCC is used), to ...
- 728
1
vote
How to benchmark two Windows PC's performance
For the CPU benchmark you can use prime95 if you are sure that both systems are stable.
Otherwice you can use CPU-Z for that.
For the GPU we have 3DMark, not yet known to crash or freeze windows by ...
- 11
1
vote
Temporary freezes even on small load
Turned out the issue was with the Kingston SSD firmware. Needed update to Firmware Revision 605ABBF0 – August 28, 2015. I assume that issue was: 520ABBF0 - Resolved a race condition where a write ...
1
vote
Low SSD Performance Adata SU650
Actually you're getting what you're paying for. I'm not claiming it's a bad drive but it's very cheap QLC, reinstall won't help. Basically what you're experiencing is that the drive is using SLC cache ...
- 179
Only top scored, non community-wiki answers of a minimum length are eligible