Have you tried the NinjaScript Utilization Monitor? Run it for a few minutes while your system is running quickly to get baseline results. Then run it again for the same amount of time when your system lags. Compare the results for an idea of what is likely causing the lag. Here's documentation on NinjaScript Utilization Monitor: https://ninjatrader.com/support/helpGuides/nt8/?output.htm
I'm one of those "hanger-on-ers" of NT7, and while I have NT8, I still stick with NT7 out of habit. Cold dead hands and stuff. I have a bunch of custom indicators for NT7, and what really bogged the shit out of it was during a tick-data rush, like during the Trump times during a bad trade-war tweet. Or like last year's crash when breakers were tripping. Every one of my indicators, and in fact every indicator in Ninja7, has an option labeled "Calculate on bar close - True or False." You set that thing to false and it calculates that indicator on every incoming tick. So when you have a FLOOD of tick data coming in during those rapid sudden thrusts, it would bog the hell out of the machine. So I had to set every indicator on every chart to TRUE on that parameter, plus increase bar size (for less screen paining) to be able to have a workspace that did not freeze up for MINUTES. I do not know if NT8 has that parameter in it's indicators as I have not loaded it up in years, but check for that.
Thanks. I'm aware of that distinction and do use it. Regarding NT 8 vs NT 7 - I think there was a LOT of issues with NT8 initially. The first version was in no way an improvement. They took about a year just to get the cross-hair working without lagging. They even had a suggestion to NOT use the cross-hair for optimum performance. WTF? Since I now have a lot of stuff on NT8 I'm kind of married to the platform, so probably won't change anytime soon.
I believe that RAM is more important than the processor. It is not worth saving much on this element of the system, firstly, because the performance of processors of this architecture depends on the frequency of memory operation, and secondly, because RAM from an inexpensive segment often cannot work stably at the declared characteristics. The amount of RAM for comfortable work in today's realities, I think, should not be less than 8GB, since even just the pages of sites are becoming more and more loaded and more complicated every day, respectively, they take up more and more RAM. It is also important that this volume is not set by one memory bar, since the memory works faster in DUAL mode.
What matters most is the speed and reliability of your network connection. An infinite number of infinitely fast processors cannot make up for 200 ms latency to the ECN or broker, or for 500 ms roundtrip per order. TWS is written in Java. All other things being equal it is a significantly higher load on the system than platforms written in C/C++. It is also sensitive to garbage collection pauses, unless one uses a JVM platform optimized for real time applications, such as Azul Zing https://www.azul.com/products/prime/. Regarding laptops, one should use a mobile professional workstation equipped with Xeon processors and ECC memory -- such as the Dell Precision, Lenovo ThinkPad P, or HP ZBook series -- preferably a model that supports dual batteries. Specify 8 or more cores, 64 GB or more RAM, turn off TurboBoost or SpeedTest, and make sure to underclock the system. One also needs WWAN support in order to be able to trade from locations with weak or flakey wi-fi. The quality and performance of the graphics card is critical for driving multiple displays. I would suggest an 8 GB nVidia Quadro P4000 as a minimum.
The most important lesson I learned during decades of professional software development is that dollar for dollar and minute for minute of engineering time, nothing solves as many problems as quickly and reliably as more memory. One should think of RAM vs. CPU as oxygen vs. car engine. The fastest, easiest way to make cars run faster is to pump more oxygen into their engines.
My trading comp is a 10 year old HP Z workstation with 64GB of RAM. I rarely go over 16 GB though. All I've done is fans replacement. No other moving parts in it.
I also use a pair of HP Z820 workstations with 64 GB each in a hot standby failover configuration. The hardware is reliable, however HP support sucks and HP no longer provides driver updates for these machines. I am replacing the Z820s with a pair of Dell Precision T7910 workstations with 256 GB RAM each. Dell's support has improved greatly and is now so much better than HP's.