Thought I'd start a new thread as my original one has some (v. useful) drift.
Got the Samsung 850 Pro delivered from Scan yesterday. Cloned my HGST 512GB SATA 3 Travelstar to 2 WD 512GB HDDs, just in case!
Fitted the 850 and used Macrium Reflect Free to clone the HGST to it. Didn't bother with Samsung's s/w as the purely graphical instructions showed the new drive attached to a lead.
After cloning was complete, done by intelligent sector copy and SSD optimisation, closed down, disconnected the HDD and rebooted.
OK - boot went from 2½ min. to about 35 sec. to be realistically useable!
Opening times for programs that took 'too long' are now around ¼ - ½ what they were, even when Superfetch was fully loaded (that took about 3 min.).
I'd already enabled AHCI, including editing a Reg. key before changing the BIOS:
http://www.helpwithwindows.com/Windo...ive-page2.html
Turned off Superfetch/Prefetch and cleared them, checked that TRIM was enabled and then ran some tests. I didn't save those results because I wanted to configure the SSD with Samsung Magician first.
Using Magician, I set it to Maximum Relatability then used Advanced mode to increase the Paging File from 200MB - 1GB up to 2GB and tweak the Power settings a bit.
I tried Rapid. It made the system unstable, had to reboot to turn it off as Magician went all zombie on me!
Over Provisioning: supposed to be about 10%; now, don't laugh, after 10 years on a 512GB drive I still have well over half of it unused! My OP on this SSD it 394.8GB! - that should allow a bit of leeway.
Results from CrystalDiskMark:
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CrystalDiskMark 5.2.0 (C) 2007-2016 hiyohiyo
Crystal Dew World : http://crystalmark.info/
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* MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
* KB = 1000 bytes, KiB = 1024 bytes
Sequential Read (Q= 32,T= 1) : 541.682 MB/s
Sequential Write (Q= 32,T= 1) : 520.884 MB/s
Random Read 4KiB (Q= 32,T= 1) : 273.449 MB/s [ 66760.0 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 114.969 MB/s [ 28068.6 IOPS]
Sequential Read (T= 1) : 492.474 MB/s
Sequential Write (T= 1) : 466.840 MB/s
Random Read 4KiB (Q= 1,T= 1) : 36.016 MB/s [ 8793.0 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 110.254 MB/s [ 26917.5 IOPS]
Test : 1024 MiB [C: 44.3% (18.7/42.2 GiB)] (x1) [Interval=5 sec]
Date : 2017/05/18 8:20:45
OS : Windows 7 Professional SP1 [6.1 Build 7601] (x86)
Thanks again for the advice - and the suggestion that I should have built this rig with an SSD originally was spot on! Still, I've learnt a lot in the last year or so.