The Change to 64 Bit - What Exactly Happens?

[paulyg123 135]

On the 64 vs 32 debate, what are the advantages we would expect to see?  Better graphics qualities?  is that it?  Right now I have a hard telling a P3D screen shot with a real photo.  Please tell me the advantages of 64 bit

[Lbt564 60]

25 minutes ago, paulyg123 said:

On the 64 vs 32 debate, what are the advantages we would expect to see?  Better graphics qualities?  is that it?  Right now I have a hard telling a P3D screen shot with a real photo.  Please tell me the advantages of 64 bit

no more out of memory and higher textures are definitely two advantages. We still don't know what the next p3d platform will include, maybe a new lighting engine, no one knows only the beta testers and they are under NDA. We can only wait, wait and wait.

[JamesIceland 14]

8 hours ago, mtrainer said:

The real change to 64bit is the change to the address pointers, and sure there are lots of these in the ecode as every branch will now be a 64 bit value.  But, that doesn't mean the integers in the current code base that work just fine at 32 bits will need to be upgraded as well.  Although by default the compiler may choose to take all unsigned integers to 64 bit, inside the code that is easily overwritten with a type declaration.  Code size will grow but will not double.  A small performance hit will be there, but will likely be pretty small as processors are fetching well over 64 bits at a time from main system of memory due to a computer science property called "locality of reference".

I'm not sure I understood this fully but does that suggest recompiling could be a relatively simple process for some add on developers? If so great. If no, then I have proved my point in saying I'm not sure I fully understood what you meant 

In terms of 32 to 64 bit changes, I hope that developers will continue to optimise their add-ons for a balance between visuals and performance moving forward - just because the memory limit has gone doesn't mean we will want to be flying a 3FPS through 8k cloud textures! I think the visuals now are pretty impressive as they are - I would personally sacrifice super HD textures everywhere for an optimised smooth sim performance. That leads me to wonder about the potential performance hit mentioned here - does that mean the move to 64 bit could actually reduce smoothness/performance? If so, it would mean more than just a simple recompile of current coding for the add-on developers I guess.

All guesswork I know as we don't actually know what LM are doing - maybe they are really optimising performance as a priority.  

[Cargostorm 151]

64bit - if it arrives - will be a massive hit, and I doubt that the IVAO or VATSIM software developers are currently on the boat. If not, it will take some time until we can fly with online ATC again...

[Guest]

64bit benefits:

1.  bypass the Wow64 compatibility layer needed by 32bit apps

2.  many more GP registers available so less need to write data to memory and then read it back a few instructions later, speed

3.  each register can support up to 4 arguments passed at a time, less likely for buffer overflow

4.  no limit on large continuous blocks of memory allocation, less fragmentation

5.  memory release can be deferred reducing CPU overhead

6.  most hardware has long since been designed and optimized for 64bit processing

7. no need for packed structures (which are slower, primarily used to save memory which is no longer a concern)

Memory efficiency = slower ... same as when one deletes a file, the physical space it takes on an SSD or HD is not actually cleared, just a single flag is written to mark the address location as available ... this can be wasteful, but it's considerably faster.  So being wasteful and/or inefficient with memory isn't always a bad thing when it comes to performance.

Cheers, Rob.

 

[JamesIceland 14]

 

1 hour ago, Rob Ainscough said:

5.  memory release can be deferred reducing CPU overhead

6.  most hardware has long since been designed and optimized for 64bit processing

Thanks Rob - I'm going to have to Google pretty much each point so I can really get my head around it. However, these above points really sound interesting - I'm just building my new sim so I know the hardware will be 64 bit ready and up-to-date which is great. Point 5 though sounds interesting as it suggests there could even be performance improvements from going 64 bit? I know LM worked really hard to get VAS to release previously but I wasn't aware that it may have had an impact.

Therefore perhaps add-on developers without the 32 bit memory constraints will not have to worry about being inefficient with memory therefore improving performance? Of course, if a developer goes crazy with what they include I'm sure that'll cause problems in itself!

[denali 74]

On 2/26/2017 at 0:37 PM, Noel said:

For some reason this quote comes up when I start a new comment

[denali 74]

Here is one without the quote.  This was happening after closing and opening Chrome.  heh. 

[denali 74]

Anyways, awesome sum up Rob.  Much food for thought.  Got me all googly eyed.  Thanks once again.

[denali 74]

Some of what I'm getting out of this is that there is good reason why 32bit P3d was never quite "perfected" as there isn't a point to a laser focus on tidying up memory after use if going to 64bit.  All of that concern is gone.   Concentrating on getting the right "rhythm" before use does have a point.  Since P3d calculations aren't that complex, there are just a huge many of them, there isn't a huge bonus in speed if they aren't neatly regulated.  

[B777ER 2,486]

Whatever it winds up being, I'll shall be watching from the sidelines from my super stable P3D v3.3.5. I have everything working brilliantly right now and I don't intend of touching a thing until 64bit fleshes out and all my current addons are updated and any bugs worked out. Gonna be a while but I'm in no hurry. 

[JamesIceland 14]

26 minutes ago, B777ER said:

Gonna be a while but I'm in no hurry. 

Actually, that's what this thread is about - is it going to be a while? What does it take to convert an add-on to 64 bit? I don't know why but I get the impression that LM are working hard to get this right as indicated by the partnerships they have made since the early P3D releases - these partners are no doubt going to be involved heavily in testing the new platform. We all remember the hassle going from v2 to v3 - it would be somewhat ironic if the move to v4 was actually smoother, even if it is 64 bit!

As soon as OOM's are a thing of the past, I'm in, even if it means flying in a pretty bare bones sim for a while.

[Christopher Low 5,353]

I will not be upgrading until I have a LOT more than a "bare bones" sim.

[SimonC 116]

2 hours ago, B777ER said:

Whatever it winds up being, I'll shall be watching from the sidelines from my super stable P3D v3.3.5. I have everything working brilliantly right now and I don't intend of touching a thing until 64bit fleshes out and all my current addons are updated and any bugs worked out. Gonna be a while but I'm in no hurry. 

Haha, I think I remember this post from the time P3Dv1 was released... then v2, then v3...

[DylanM 1,069]

2 hours ago, B777ER said:

Whatever it winds up being, I'll shall be watching from the sidelines from my super stable P3D v3.3.5. I have everything working brilliantly right now and I don't intend of touching a thing until 64bit fleshes out and all my current addons are updated and any bugs worked out. Gonna be a while but I'm in no hurry. 

It is great to have a second stable sim as a go-to. I'll be jumping in to V4 when it comes out, but will be using it as a "preview" until the addons I like are officially supported, and I find I have less and less pull to jump back to V3...it'll be a while!