The way the os acts is explained in microsofts technical papers. you can search for more info at microsoft technet.

For your a,b,c questions i'm not sure for the answer.But i think it will fail. Everythings it is going to work, if the availiable virtual memory (inside physical), is enough to fit the size of the process. I 'll make some experiment to see where is the limitation to me, as i use 4gb memory without swap.
For d,e,f i think that you sould get an error.

I think that everything is gonna work if it is below 2gb.

Peter it's a little bit difficult to me to explain, cause english is not my native language but i 'll try.

It is nice that you make expiriments with memory, as your program, use it in a way that performance is very critical.
It 's impossible to me to answer to the above comments, because we 'll get lost in details.
You can't just look in the task manager properties, to see what the memory management of windows have done with memory, because you see just numbers, but you don't know from where (which application) this data comes.

It is more easy for me to explain, how the os acts, when an application requires memory from the system.

All this conversation is important, if we use a 32 bit os (it doens't matter which one). At 64bit we don't have remarkable limitations (we have but, the limitations come from hardware).

Let' s take the following example, that we have a system with 32 bit processor and 4gb of physical memory. I use this example, cause it contains all the others circumstances like 2gb etc...

A 32-bit processor uses 32 bits, to refer to the location of each byte of memory. This means 2^32, about 4.2 billion unique locations. Let's say 4 GB. Those are all the possible addresses of memory, that the cpu can use. So above this number the cpu just can't see those locations and can't use them.

Let's go now to the OS side, in the above example.
It is built in a way, that every single application that request memory, has it's own VIRTUAL 3gb memory space.
This means, that every application acts like there is ALWAYS* 3 gb of (VM) memory to occupy, independently from the fact that for sure this space doesn't exist in physical memory. So this application starts to PAGE it's data, in a continious virtual space, until it get's all the data to that space.

*The only limitation to this come from the OS, which have the "central'' management of memory and can stop this procedure, (paging) if the application allocates so much space. OS manages all applications paging procedure, in a way that the available PHYSICAL memory & the SWAP file doesn't run out of space.

This can happen, when the os prefetching the most used programms OR when an application requires much space in physical memory like xxengine process.

The 4 gb of our example are devided by the os, to 2gb kernel mode space (os kernel, bios, shadow memory, agp aperure size, etc...) and 2 gb for ALL applications space. (this can be changed with some  tricks to 1/3).

As i said to another post this virtual memory is a mix of space in physical memory and hard disk. If an application requests the vm data,
then a procedure take place and this addresses are translated to physical memory addresses, so that the application CAN USE them.
While this data are not translated into physical address space, only OS knows about them and no application can use them.
So for this translation if we have the swap file disabled, this operation takes much shorter because the hard disk doesn't participate.
This is the benefit.

So if a process from one application that is not in use , allocates about 1gb in virtual memory and you start a 1,8gb wav (1+1,8=2,8 that is bigger than 2gb max for apps) the os will translate, this 1,8gb to physical memory and at the some time it will release the data of the old application so that this 1,8 will fit.For sure this requires cpu assistance and will create clicks and pops.
 
On the above paragraph i said that 2gb can be translated in the best case, because in 32 bit windows this physical space of memory is the maximum that all the applications (user mode) can allocate.


I hope that the above are clear to understand because it is not so easy to explain.


PS: You will never come up with critical errors for OS, because when the physical memory running low, the operating system will release some space for the process that need this space. Don't forget that kernel modules will always have availiable memory in the 2gb kernel space.

 

OK peter please delete the posts,are unrelated to the subject. But i  still believe that you haven't understand...
Please read carefully. It 's no so difficult anyway..

For sure when we have to deal with big files then it is not recommended, because obviously it will cause xxengine to close BUT
when we use the regular 44.1/16 wav files, a 1,4 GB memory is enough for about 2 hours playback.


I don't mean that the swap file goes somewhere else, i think you haven't understand what i'm trying to say.

The swap file is not exactly the same thing with virtual memory. It is just a part of VM.

Virtual memory is a memory space for the os, that it constist of a space in physical memory (the size is controlled by the kernel of os) and
the swap file, a space on the hard disk. By disabling the swap file, you just allow system to page memory to the physical memory only.

When a program needs this data from the page table, a chip insude cpu the mmu (memory managment unit) "sends" a request for this data to move from the vm, to the physical one. So if this data is allready to the physical memory part of vm (if you disable swap file this happens all the time) , then the os just translate those virtual addresses to physical memory addresses. This translation is much faster with swap disabled.

I know all this brings headache, but just try it and if you don't like it, is easy to set it back.

Hi peter

The virtual memory of windows (vista,xp etc..) is a mix of physical memory (paged physical memory) and hard disk space
(pagefile.sys).
With the above procedure you disable the part of virtual memory, that page data to the disk. After this you can also delete pagefile.sys from your disk because it is not in use.

You cant disable the entire virtual memory, it is not allowed by the OS.
I'm working with the above setting for almost 2 years and until now i haven't saw any error on screen.
My physical ram is 4gb, but i have also try with 2gb and i get the same results.
Some programs like adobe audition can show a warning that virtual memory is disabled, but you don't have to bother about it.
This procedure cannot create Blue screen or something bad to your os.

Also a good idea for those who have enough memory is to disable the virtual memory.

Windows have a built in function that stores some data to c:\pagefile.sys (hidden file) and load them to memory, as soon as you run the program that those data belongs.
You can disable this from my computer (right click)> properties> advanced system settings > advanced tab.
Here in the performance area click settings and in the advanced tab you can find the virtual memory.

Click change and set it to no paging file.

I f i understand well, by doing this i remove 1 bit (or 2 V=-12) of info that contains noise and distortion and is very difficult to hear anyway.
It will be a good idea to set dac is to 44/18 bit, and what it will be the result of this action for this 1 bit?

I ask all this questions just to understand how to handle Q1 and what to expect from this everytime it changes.
For sure many things changes and it's difficult to understand what is better. I understand its also hardware depended, by means that it behaves different as result, with everyones dac, soundcard etc. Also i understand that those settings, behaves different with other recordings. But for sure is less difficult to have a target and try to adjust Q1, to achive your perpose and this is the reason for all the questions.

This has to do with the output latency, i mean 1ms is the same for all Q1 settings?
Or it has to do with data output, for example lower q1 sends, (how to say) more "accurate" signal to dac.

Another question here has to do with phase. When i hear at -4 region if i don't tick invert phase the sound is very unconfortable.
At +2 or +4 the difference is not so huge, I'm not sure what is better. Is there any explanation for this?


I think "digital" is not the right word. I saw in another post someone else use the some word, but for my ears i have a feeling of more analog,detailed and comfortable playback. I dont know if my tube amp has any influence in this. I want to hear some seperated instruments sounds to verify that. With music by lowering Q1 i get more pleasant sound.

I hope not to bother you with all these questions

OK peter thanks again for your help.

Is it possible that the distortion i get at -1, -2 etc is from the output buffer of xx?

Peter i think i found something...

Upsampling at 16 bit is ok. I roll back the drivers of the soundcard and now i get normal sound until q=1. at 0 i hear clicks and pops
and below 0 i get the same kind of distortion i had with the old driver. i' m little tired to test right now, but it seems that the previous driver had smaller input latency than this one. So i suppose that the only problem for now is why exclusive mode rejects 24 bit in xx.

Another question i would like to ask you, is if xx take care of the clipping that sometimes creates the upsampler in some recordings.
What is the difference between double & upsampling to double, upsampling and AA?

I get an error. i can't use 32 bit BUT for me vista sp0 have bad impact to many other things including speed, latencies etc.
I can't use q=-4 with sp0. I recommend to anyone to use 2008 or vista sp1. especially all the users that have a good soundcard with native 44.1. Give it a try, i'm sure you gona like it.

Ps: vista sp1 is not exactly w2008. It is difficult for a simple user to set up 2008 but for power users is quite easy and much faster than vista.

Peter i have 2 things to propose. I don't know how difficult is it to accomplish.

First of all you can try with your onboard soundcard, to work at 24 bit. All this cr*py soundcards behaves the same.
They resamples 44.1 input to 48, before send the signal to spdif. If you choose 44.1 as output they convert again to this samplerate.
So we have 2 convertions and this is what i want to keep out of, with upsampling to 88.

The second is if possible, to modify the code of xxhe, so that if someone choose 96/16 or 192/16 (at dac is) the upsampling is kept at 16 bit depth or to have the option of 16 or 24.

Anyway i appreciate your help and your hard work with this program.
For me even at 44>48>44 khz xxhe sounds much better than foobar.
It is the winner by far

the one you propose to download yesterday.

OK peter sorry for the misunderstanding. I will try to be as more accurate as i can.
forget about the above posts.

Using the latest version 09v-3 as it is after download (i don't know if any registry value must be deleted before i use it)
with the new 96.dat file.

If i set dac is 96/24 (engine 3, double & upsampling checked) and play a wav, i get endpoint create failed > the dac does not accept the byte sequence, and engine exe doesnt start. The same with only double checked.

If i set dac is 96/16 (engine 3, double & upsampling checked) and play a wav, my external processor locks at 88.2 but the output is distorted.
nothing hangs in this case.

If you want any other information please ask.

Now lets go to foobar.

After a clean installation, and using the necessery plugins ( wasapi out, and a resampler), 
i check as output wasapi, buffer 100 and output format 24bit. I set the dsp resampler at 88.2 and play a wave.
My processor locks at 88.2 and the output is ok. the same happens, if i set as output format 16 bit.

I think that if upsampling in xx was at 16 bit, everything would work fine for me. for some reason there is a bug in xx or in the driver that doesn't allow 24 bit with it.

thanks again for the help.