With the box I had, running the TWS windows to present the charting data I'm accustomed to, TWS response was initially o.k. with the 1024 Java Heap parameter. The longer the platform was up and running from Market Open, the slower the response of the platform became. By mid afternoon, when clicking on a price in Book Trader it would take SIX SECONDS for the Transmit button to pop up. Lag in an order from a Chart Trader button populating tables would take seconds, with additional fewer seconds required before it appeared on charts. Trying to adjust parameters of the platform would often open a configuration window, but items were not selectable.
This is not tradeable.
Closing TWS and restarting it would resolve these issues, but response was just restored to its original slowness. (reminder - I'm running a lot of charts on four monitors)
So, I decided to try Win7. With the same hardware, and a spare hard drive of the identical model/size, I loaded the new OS. In getting 6.23 Java, it noted that while I was asking for the 64 bit version, it noticed I was using a 32 bit browser, so it suggested getting both 32 and 64 bit Java so Java in the browser would work. I installed the 32 bit java, then the 64 bit java. Then I downloaded and installed TWS 913.6, same as I was running before. Also installed the same anti-virus (avast) and Firefox.
TWS loaded right away and I was able to sign in first time. Rather neat to see my charts all open up on the new OS! ;-)
I was able to make copies of the shortcut that launches TWS, with the Java Heap set to 1024 and the other to 2048. TWS launches and runs with both, with no difference that I can note. I have no idea which Java engine TWS is running with, be it 32 or 64 bit.
Core usage has changed. While one core is significantly loaded more than the others, the difference is far less and all cores have less load, almost half of what they had under WinXP. The character of the cores' load is different: the load is more sparse, in that the load has way more time at the lower end of it's range between spikes - the average is down. Overlapping one chart with another results in no noticeable change in the CPU load. Minimizing a chart reduces the one core load, but that is less significant as that core's max was down so much from under WinXP. The box produces less heat...
Circling the mouse still pops the one core, but to 60%.
How does TWS run? Response of TWS is faster at everything! It runs much better. Lag between charts of the same security at different time frames is much less. Under a half second. Chart Trader button orders populate tables in under a second with another half second to appear on the charts. Multiple button clicks queue orders and there's an additional lag while it catches up, but not the huge delays like under WinXP.
Unfortunately, by 11:00, response to Chart Trader buttons is starting to lag. By 1:00, is is so significant that it feels it would be unsafe to trade.
On to next solution.
edited: I believe that the difference is largely due to an entirely different type of graphic driver under Win7, with much better use of them being made by either Java or Java's calls to Win7. Don't know enough technically...
