There are a few things that every AWIPS user should know about how CAVE and D2D load data and manage memory and the workstation. This can significantly improve the effectiveness of your displays and help you manage workstation performance. 

So, each CAVE has 6GB of memory reserved for it, at least that's what it is right now. If you try and launch more than four CAVES on an LX workstation, you'll get a pop-up message that'll say "warning, you've got too many CAVES loaded" and you'll have some memory problems. So, right off the bat, just know that each CAVE reserves 6GB of memory, and it's not a good idea to load ten CAVES just for the heck of it. It's, you know... you can easily load three CAVES and four CAVES if you need it, but, you know, don't unnecessarily load CAVES just because you feel like it. 

So each CAVE has 6GB of memory, and let's go ahead under the file menu, and under procedures let's open up our RAC18 procedure under site... RACFY18, let's double-click on it. We're gonna use this throughout this session so let's go ahead and put this off to the side. I'm gonna load first one of the more memory intensive bundles here. Let's do the RAP hail threat, double click on this. And let's watch the memory usage at the bottom here. We see that this bundle uses quite a bit of memory, and if I hover over that we can see it's gonna be reserving 2GB of memory for this bundle. And, as each one of these derived parameters are calculated... grid data is unique in that, for something like the CAPE display in the upper right, it actually goes out and gets all the temperature, dew point for every grid point, and it calculates this on the fly. 

Then that's a real memory intensive application, and once the derived parameter is done with that calculation it's going to free up that memory and a process is going to routinely run to clean up that memory. So, we see... if we look at that display on the bottom right we see we have 6GB are our max, and we've used up about 1GB of our 2GB total for this request. And a lot of that size had gone up, and then the garbage had been collected and it had brought that memory back down. But that garbage collection process for the memory isn't always... it doesn't always collect all the garbage. So you'll see that there's this little tool over here with this icon that says "run garbage collector." When this gets up to 6GB... and you're gonna see that go red, and it can highlight for you when you're starting to have memory problems, and maybe some of that garbage collection hadn't been run. So you can always manually run this garbage collection... doesn't hurt anything. 

Let's see what happens when we left click on the garbage can, and we see that the amount of the heap space went down to 500 MB, and the total gigabytes used for this bundle is now 1.9GB. So again if that's getting up to 6GB and it's red and you're having some issues, then going ahead and... and running garbage collection manually is one strategy to consider. 

So the way we're loading data right now is kind of old-school. We've got our four side panes, we can right-click on one of the small panes and it's gonna swap the display. When we right-click on that small pane again we see that... we go down here on the bottom it's re-requesting all that grid data, and it's reloading all that memory again. It's kind of using this again to load in all these displays, all 16 frames, and recalculating everything. So there's an inherent cost in swapping panes using the the 5 pane layout in D2D that uses up more workstation performance. So the idea at least with this display is that you can have multiple things loaded. Let's go ahead and right click on the small pane in the upper left. 

And then if we go down to our procedures tab on the bottom here... and we're going to load up, let's say... let's go ahead and load up our GOES 14. Let's see once we have... this is the active tab, it's going to load it into the active tab. I can right click on the second small pane, and I've got the... the new active tab here. I can left-click on the procedure. Let's go ahead and load in the nine panel KCRI no-flip. Double-click on that. And if we left click on the display and scroll, zoom in, hit the up arrow... you can see here's our storm... so we can swap panes here, and let's go ahead and click on our procedure again. And this time let's click the alter button, and step through loading a different radar... let's check the radar checkbox, left click on the button here, and up at the top we're going to select KFDR for the Fredrick radar, and then click load. So once that comes up we can left-click on the display, zoom in, hit the up arrow, and see now we've got multiple displays. The tab didn't change because that's... the name of the tab is what you see in the procedures window, and that didn't change when we altered it. So let's go ahead and change the name to be something that represents the radar that we just switched it to. 

Alright, so now we have multiple radars and other things in the display where... we could drag that out a little bit and we could have some flexibility in how our display is configured. We can even move these small panes up and down a little bit, but they're all kind of grouped together, and there's this inherent cost in right-clicking in the side panes in having to reload the data constantly. So that's kind of the old-school way of the initial design of AWIPS of loading in data and managing through the small panes. 

But there is another way to load data that is just using multiple tabs, so let's go ahead and try this. To use the multiple tab approach we can just right click on the main tab and go "new editor." Once we've got a new editor in here, we can load products in here manually. Let's go ahead and click on our procedures window, and if we click on SRAD MRMS, let's double click on that and load it. That's our active tab. If we want to load something else in this grouping, then right now if we click on another product like the meso CAPE... let's go ahead and double click on that, and we see it's gonna replace what's in the active tab. So every time we want to add something new to our tab displays, we have to remember to left-click on this and... and right-click on the header, and choose a new editor. Now, I want to get rid of the content that's on the left in these small panes. We see over here, I can drag this over the left and it's constrained to be 10% of this display size that's limited by the Eclipse under the hood in CAVE, unfortunately. So, once we've got our new tab here, we can right-click on this display, and if we're going to effectively get rid of this we don't want to leave anything in our side pains because that's gonna take out memory. So, I want to clear out this memory intensive display because I don't need it anymore. So I've got my... again, my third tab over here. If I right-click on this display in the side pane, now I've got my GOES data on my main bar. If I could left-click on this, I'm gonna add a new editor. And let's get this last radar bundle over there. 

Alright, so now we've got two radars and some mesoanalysis stuff all in one grouping. So again if I want to get rid of this sidebar over on the side to have all my display available, I can't do it but there's a trick. We go up here to the upper right and click on the maximize button... pushes that over into these little tabs, and we've got the full display for display. So that's handy... the other trick on this, if we want to go back to the side panes, we can left click on that restore button and we've got our side panes back. But since we're not using them we cleared them out. We're going into just simple multiple tab layout, then we're going to maximize that. There's another trick to that... instead of having to find that small space on the button, you can just go and double click on the bar here and that'll do the same thing. It triggers that maximize. 

Alright, so now we've got our displays, we can drag our tabs around how we want. We keep it on the bar here. Let's move our radar stuff over... all the way over and drop it... so we drag and drop. So let's left-click on the meso, and we're gonna move that over to the right. So now we can just switch tabs by left clicking on the tabs. And the other cool thing about multiple tab displays is that... let's go ahead and hit the up arrow to get... get our data back here... let's say we want to make split window displays. We can left-click on the GOES tab, and we're gonna drag this over to the right side of the display and make it a split right-hand side GOES... the left hand side will be the all-tilts. I want more space in my all-tilts, so I can just left-click and drag that over. If I left-click on my meso CAPE, I can cross that line, drag that all the way down to the bottom, and if I put it right about here I can split it vertically. So that looks like a nice layout. I've got my all-tilts radar data maximizing the display so I can see the most number of panels and... and make that as readable as possible. If I left click on any one of these displays, I can zoom in and maybe set this, you know, how I want for each display. I'm gonna left click on the meso CAPE, and let's go ahead and hit the right arrow... go forward in time, and zoom in a bit. And if we hit the dot key on the keypad, then we'll see that this is a really nice display of CAPE with radar data overlaid on it. It's 22Z, 23Z... so this is a really slick way to keep our situational awareness about what the environment is doing with our storms, and that's moving over to CAPE maxima... so that's kind of a nice display to have in this split window display. 

So you can have a lot of flexibility with multiple tabs. There's no cost in terms of left clicking on each one of these tabs... it doesn't reload the data, it's all loaded into memory so it's all available. So, takes a little time to set up, but there's one trick in using multiple tabs that everyone needs to be aware of and that's the... go under CAVE and load "Save Displays"... we want to save a perspective display for the D2D perspective and how all this is configured. And we're gonna type in... let's call this "Warning meso-a" for mesoanalysis... click OK. Now let's go ahead and clear these displays. Clear button. I can left-click on the map tab... let's just go ahead and hit the Clear button here. Left click on the GOES... left click on the X for the meso... yes I do want to close it. Alright, so now it's clear, clean. Let's left-click on our CAVE menu under the "load saved displays"... let's go ahead and load it back up. Double click on it, and this is going to load all those bundles which is gonna be a really memory intensive task. It's gonna throw up a wait message... I'm gonna go ahead, instead of force quit, I'm going to wait while this loads, because it will take time to load your perspective displays because you are doing a lot of things all at once. But you really just... you don't do this frequently, but you do this when you come on shift and you want to get your workstation set up. One thing to realize... let's go ahead and left-click on our meso CAPE to make sure everything came back like it should... restore it to where it was... there's our CAPE display, that looks good. I'll left-click on my radar and click the up arrow to get my storms in there... so, yeah, only thing that didn't happen was this bar didn't get collapsed. So the save perspective displays don't remember that, and you can just double click on that tab header right in here... and that is going to collapse that over, and now I've got my display. So, multiple tabs... positive thing. Using the saved perspective display is going to allow us to flexibly get this stuff back, but you gotta remember to collapse it out to get rid of the side panes. 

Alright, so there's a few tips in all this for how to manage your memory on your workstation that can really improve your... effectiveness of your displays as well as the workstation performance. One is: keep it simple to avoid performance problems. So, when AWIPS2 was fielded, I think a lot of people started to just load in a lot of data, as much as they could possibly need and use, but it ended up having workstation performance problems and memory issues, so I think a lot more forecasters over time have... have found that just keeping it simple to start with... only load what you need, you don't need to have that 200 frame GFS CAPE loaded and left there that whole time. So, load what you need, and then as you go, you know, kind of clear off the stuff that you're not using. And then, you can add stuff as you need, as you go... but, to start with, keep it simple. 

Next is pay attention to the amount of data... it's not the number of tabs, it's the amount of data that's in the tabs and your editors that's going to use up the memory on your workstation. So you want to pay extra attention to your frame counts... a lot of people are going to 200 frame counts available for GOES data, which is great but it comes at a cost. So if you don't need that 200 frame GOES... GOES loop with four panels of it, you can cut that back to 40, or 20, particularly if you're having memory problems on your workstation. You can trim those frame counts back when you don't need it. By all means, use it when you need it, but if you're not using it then you don't need to have your frame count so high. 

The other thing to pay attention to is the scales for model derived parameters like CAPE. Again, because it's got to load in the grid point data over every grid point and do the calculation... you do that on a CONUS scale you're gonna use up a ton of memory, and if you're not using CAPE... if you're using it more on regional scale than CONUS scale, then if you've got memory intensive applications you can trim those back to the scales. That's a unique thing for grid data, where it only loads in data relative to that scale for that data type. So, pay extra attention to the scales for model data when you've got derived parameters like CAPE that are being computed, and that should help you know at least which one of your... your bundles have... use up a lot of memory, and what you can do to... to limit that. 

Another thing to consider using is the multiple tabs instead of using the side panes. Again, when you swap the side panes it reloads the data, and that isn't happening when you just click on the tabs itself. So, if you do have memory problems... you can, you can have this pop up message, you can have slow loading, you can have CAVE crashes... when you get into that kind of behavior you can do a few things. You can spread the memory intensive bundles across multiple CAVES, because again each cave has 6GB of memory, and if you have all all your GOES data on one CAVE, and that thing is slow, you can split those up amongst multiple CAVES, and since they've each reserved 6GB then that can spread the wealth and the performance across multiple CAVES.  

Another thing is limiting your frame counts and grid scales in your memory intensive bundles if you're having, you know, particular problems. And, lastly, you can always run that garbage collection... just left clicking on that garbage can on your display, and that can help at times. 

So, these are all tips to consider for how to improve your effectiveness of your displays and your workstation performance. Hopefully that helps