Scan slows everything down - Where's the bottleneck?

For the past several months, a full scan more or less slows down everything else I’m doing, mainly loading pages in browsers, And considering that full scans take upwards of four to five hours, it’s not a minor deal. I’m wondering where to look for the bottleneck, as it didn’t used to be this way with Comodo (for years). Any ideas? Thanks,

CIS 8.20.4792 (free)
Win 8.1 Pro x64
i5-4690 cpu (not OC’d)
Gigabyte Z97 mobo, 16gb RAM

Clean out and defrag your hard drive (unless it’s an SSD). The single biggest cause of poor computer performance is the hard drive (which is why SSDs are so popular).

If your hard drive is more than about 80% full then copy the least used data off to an external drive, or just delete it if you no longer need it. Ideally you want your hard drive something less than about 60% full for best performance. The more data on the disk the longer your average seek time will be (the time to place the read/write heads over the wanted data).

Then defragmemt your hard drive. Fragmented files massively impact the disk response time, defragging will make a big difference. Ideally you want to use an optimising defragger (like Ultimate Defrag from that allows you to place the files and folders on your disk in the most efficient manner. Very active files should be clustered about the MFT, whilst little used files and folders should be written out of the way on the inner tracks of the disk.

Thanks. The system/programs drive is a just over half full SSD. The three storage HDDs - 1T, 2T, 3T, all 6 gb/s - are monitored by O&O Defrag. One of the three, the media files backup one, is 80% full. The other two 50-70%. That aside, I wonder if certain kinds of files, such as Windows and Todo style full backups or other similar kinds, including archival types, slow things down. I’ve noticed that much of the initial hour or so of scanning goes to the HDDs, rather than the SSD.

Run the Windows resource monitor whilst the scans are running to see what sort of HDD I/IO times you’re getting. The Windows performance monitor is a handy tool too, by default the data gatherer only runs for 60 secondsbut if you spend the time getting to grips with it you can change that to anything you like (longer data gatherer times beans a bigger output file of course). That will show you where the bottlenecks are. It does sound like HDD though, that’s a big storage farm you have there…