I've been regularly adding torrents that I leave seeding and I've noticed a funny behavior. When I am viewing items in a category or looking at my bandwidth I'll upload at a high speed (it varies but generally between 5-8 megabytes/sec) but when I switch to viewing all the items I'm seeding or all items (currently a little over 9000) the speed will always drop to around 2 megabytes/sec (i.e. observing the transfers changes them; my lame quantum mechanics joke). This will happen whether or not Tixati is actually displaying (so I need to always remember to avoid that view when moving on to something else). There will also be a freeze for a couple seconds when switching into or out of those views during which transfers seem to stop entirely.

One other curiosity: I sometimes find when downloading a significant number of torrents that transfers will slow down and enter cycles of stopping and starting with a lot of narrow peaks in my bandwidth graph. At the same time initialization of files also slows dramatically. After trying shutting down everything else didn't work I experimented and discovered that my Windows anti-malware was eating a significant number of cycles (still only a few percent) and when I turned off active anti-malware the problem went away. This works every time there's a problem. I don't know if it's choking on scanning my downloads or what but since the downloads have always been media files from reputable sources turning it off for a little while hasn't been a problem (it automatically turns back on anyway).

just to clarify: when you are on the transfers tab, your downloads slow down?

what view is your transfers tab on(tree, tab or split)?
if on tab view, what bottom tab is usually showing?

do you have files, trackers, pieces or peers showing or merged?(is there an arrow to the left of the torrent name?)
are most of your files actually running?

what do the diagnostic graphs look like? they are under help->diagnostics.

no hijack intended but what _is_ the arrow left of the transfer since I now see them in 2.43?

I only have 15 torrents on a (weak) cloud machine, when I'm on the transfers tab I get 2-3mb/s... any other tab I get 5-6mb/s. Even if you minimize on the transfers tab it stays slow. So I always have to remember to not leave tixati open with the transfers tab open...

...its also interesting that it always takes the same amount of CPU (almost none), no matter what tab. So its not that all the details on that tab are slowing things down.

Anyway, just wanted to confirm your observations. On my local physical box this does not happen.

Transfers more specifically the transfers pane, or having any other Property pane up with either Pieces, or Peers up... it's a resource thing.
I can tell you this, Tixati has ALOT of windows "hidden" most of the time. It's simply a matter of your client paging out that info... Unless your client is already using over 1000 MB of RAM and this happens I would say do less things concurrently so that you're not having to wait for the update from pagefile.
Remember on the Transfers pane, there is a scrolling line for EACH file(s) in there with not 1 but 4 counters. That are polled every second.
Pretty sure this is the case even when you turn off all the time-based columns under Layout -> Select Columns -> Transfers view.

btw: why isn't the Pieces or Files tab on that dialog? I had an issue with columns being "hidden" i.e. too small to click/see what's in them. (Fixed by right click -> Properties to open the separate tab, closing that properties tab and resize of the main Tix window.

Anytime your left column switches to <-> from All Transfers ... it lags to load all those lines. (Slight workaround turn on Filters, keep it selected (blue in all color schemes) for what you're searching for. I notice this load-select is less lag than actually switching away from ALL transfers)