Macbook Pro upgraded with SSD and 16GB Ram still running slow.

1) +1 on evicting Kapersky. You might wish to search for "kapersky banned" to see how Western governments have felt about having it on official devices. NO anti-vurs in needed.

2) The specs of your SSD are correct but this is definitely not:

Performance:

System Load: 2.00 (1 min ago) 2.40 (5 min ago) 5.32 (15 min ago)

Nominal I/O speed: 0.30 MB/s

File system: 121.09 seconds (timed out)

Write speed: 175 MB/s

Read speed: 169 MB/s

The timed-out file system test could indicate a compromised drive cable. Your write/read speeds should be closer to 500MB/sec. As repoertd here, best SSDs for Macs seem to be the Crucial MX (not "BX") series and the Electra series from OWC. I saw another post yestarday with eh same Samsung drive as your that was not running up to speed either. I have the OWC Electra 6G series SSD in my 2012 Macbook Pro and it posted these scores in EtreCheck:

Performance:

    System Load: 1.61 (1 min ago) 1.60 (5 min ago) 2.94 (15 min ago)

    Nominal I/O speed: 0.15 MB/s

    File system: 28.20 seconds

    Write speed: 487 MB/s

    Read speed: 482 MB/s

Big difference.

3) Uninstall CCleaner. It is trying to earn a career as a crash-test dummy:

2022-01-24 22:24:31 com.piriform.ccleaner.CCleanerAgent Crash (20 times)

Macs need ZERO cleaning apps because the macOS, cat-like, has been self-cleaning for 20 years. I tested CCleaner and it slowed the 4-core i7 iMac I used for testing.

4) Sometimes several safe boots can help sluggish SSD scores. Instead of the usual sequence of "boot to Safe Mode, then boot to regular mode," let the computer sit for 30 minutes or so in Safe Mode to give SM time to check and clean up. More info on Safe boot/Safe Mode here:

How to use safe mode on your Mac - Apple Support

Rajiv Choudhry wrote:

MacBook Pro Late 2011 upgraded with SSD and 16GB RAM is still running slow. I have done a done back up followed by a complete reinstall of High Sierra but it takes more than 15 minutes and sometimes much longer to boot. Also the opening of any new app takes ages.

I have lately installed MS Teams as it si esssential for my organisation.

Do I need to change the HDD/SATA cable too as I did not change it while changing the SSD.

I have done EtreCheck Pro test.

If your SATA cable is suspect— to test pull the drive out and install it in an external enclosure, This will bypass the internal SATA and booting externally (holding the Option key) may be telling if no issues...

easy enough to replace without breaking the bank:

OWC/MacSales Apple Hard Drive Cable For 13-inch MacBook Pro (Early/Late 2011)

https://eshop.macsales.com/item/Apple/9229771/

See all OWC/MacSales partners/ reseller around the world:

https://www.owcdigital.com/reseller/resellers

Since the 2011 laptop only has USB2 ports, booting from a USB drive will still be slow since it will limit SSD speeds to about 250MB/s at most which is still higher than what the EtreCheck report was giving for the speed of the SSD installed internally.

I haven't really seen any reviews for the Samsung QVO SSDs, but I believe they use really slow QLC NAND so the performance of the SSD could be slower than some older models under certain conditions. I believe the 870 series is the first Samsung SSD to utilize the QLC NAND, so there could be some bugs in the SSD for Samsung to iron out. I know that in general some Samsung SSDs have slowness performing certain tasks while an SSD may perform extremely well on other tasks.

What is the make & model of the memory upgrade? Macs are very picky about the memory they use. Have you tried running the Apple Diagnostics to see if any hardware issues are detected? The diagnostics may complain about the Samsung SSD and may even note that you are using third party memory (both errors/notes may be Ok). You can also try running Memtest86 to check the memory. You can use the downloaded Memtest86 .iso or .img file as a source for Etcher to create a bootable Memtest86 USB stick. Option Boot the Memtest86 USB stick and select the orange icon labeled "EFI". Once the test begins, you may remove the USB stick.

Start troubleshooting by uninstalling Kaspersky.