GSIF audio performance

[tonylombardi]

I\'m using an AWE64 Gold ISA card, but will soon get a GSIF compatible card. Not sure which yet.
I\'m getting some slight clicks in audio when GSt hits over 100 voices in my sequencer, which is running on the same machine (800MhzPIII Coppermine).
My question is, can I expect these clicks to go away when I upgrade to a GSIF card, or is the cause of the clicks something else? I know GSIF improves latency, but does this also get rid of clicks? My Gigs are on a Maxtor Diamondmax 40Gig running in ATA66 mode. Also this is running GSt without effects.

Thanks

[Chadwick]

I\'d really like to hear an answer to this.
I\'ve always read that clicks and pops were a result of slow drives, low ram or crappy CPU - not so much the sound card.
You have what seems to be all the right stuff though.....
Are your gigs on the same drive as the programme?
This was at the Nemesys troubleshooting page:
Noises

Some video cards are known for conflicting with sound cards. This can result in noise during the playback of a
sequencer or when moving on screen knobs and sliders. If you experience this, you can either experiment with
different video cards or simply minimize the sequencer when doing final recordings. You may also find better
performance with a slightly lower graphic resolution.

If you hear occasional popping in the audio, try setting the following option for your hard drive: (NOTE: first check
with the manufacturer of your hard drive prior to changing this setting to confirm that the high speed DMA mode
is supported)

1.Double Click on \'My Computer\'
2.Double Click on \'Control Panel\'
3.Double Click on \'System\'
4.Click on the \'Device Manager\' Tab
5.Double click on \'Disk Drives\'
6.Double Click on the Drive icon corresponding to your hard drive (i.e. \"GENERIC IDE DISK TYPE01\")
7.Click on the \'Settings\' Tab
8.Place a check in the \'DMA\' checkbox
9.Click \'OK\' (to close the \'Settings\' dialog) and \'OK\' (to close the \'System\' dialog)
10.Click \'Yes\' to reboot your computer.

We have found this high speed DMA setting to greatly improve disk performance and eliminate occasional poping
on systems that exhibited occasional popping.

[Doug Bircher]

My understanding of the new 7200 rpm ATA66 hard drives is that there will not be a DMA box to check because DMA is automatically part of the drive/controller.

[cc]

<BLOCKQUOTE><font size=\"1\" face=\"Verdana, Arial\">quote:</font><HR>Originally posted by tonylombardi:
My question is, can I expect these clicks to go away when I upgrade to a GSIF card, or is the cause of the clicks something else? My Gigs are on a Maxtor Diamondmax 40Gig running in ATA66 mode.
<HR></BLOCKQUOTE>

Asuming that DMA is in use, polyphony depends on the one hand on hard drive seek time, and on the other on CPU power. (Well, in theory. Then you have the flipside of the coin, which is contention of various devices on the PCI bus. The new bus architecture of the i820 should go a long way towards fixing this - if only the chipset were actually feasible http://www.northernsounds.com/ubb/NonCGI/images/icons/frown.gif )

If you get clicks when the CPU still has headroom left (like at around 50%), the problem is probably due to seek time.

I\'ve noticed an odd thing which may answer this question; maybe some of you have some comments on this:

What I did was to use Sisoft Sandra to benchmark my ata66 drives. I discovered the following:

When plugged into my on-board IDE controller, Sandra gives an estimated seek/access time of 5ms (which is about right for beginnig of first partition).

However, when using a plug-in IDE ATA66 controller (in my case an Iwill using the Highpoint HPT366 chipset, with latest drivers, etc.), the seek / access estimate went up to 33ms!

Although the sustained transfer rate did not go down, I believe this increase in seek time is *bad news*. Reason is, Sandra gives another benchmark which is *random block read throughput* (i.e. the throughput you get when the head is jumping accross the disk to read various blocks), and I reckon this is the important parameter.

Whereas sustained transfer rate may be around 22MB/s, the random block read clocked in at 8MB/s for the 5ms seek time, and around 1.5MB/s for the 33ms seek time... The lower the seek time, the higher the random block read rates, because that throughput basically depends on an average of how long it takes to get to the data and to read it.

What Giga does, basically seems to approximate random block reads (I reckon it reads, in circular fashion, a block for each separate voice currently playing) Thus, the latter benchmark probably gives the best idea of how many voices to expect. I.e., each (mono) voice requires 44.1 * 2 kB/s (say).

On my system, for the estimated random block read throughput of 8MB/s, this figures as:

8 * 1024 / 88.2 = 92 voices. I seem to get around 110 voices before slight clicks set in - the difference probably owing to the fact that the GSt accesses aren\'t *completely* random, but follow a pattern. (And because benchmarking only approximates the real scenario.) This is on an 800MHz P3, 256Meg Ram.

So, the motto seems to be:
a) to increase polyphony, increase the random block read throughput

Some ways to do this are:
i) go for lower seek times, e.g. use first partitions, SCSI, etc.
ii) Spread your Gigs over multiple drives so that GSt can access them simultaneously (haven\'t tried this personally; comments?). In this case, make sure that each IDE drive is on its own separate channel (i.e. no master/slave setups). Also, I reckon you would then not see increased polyphony if you are only playing instruments whose gigs are stored on one of the drives.


b) It also seems to be wise to stay away from PCI add-on IDE controllers... I did not actually see what happens if I run my Gigs via that plug in controller - by the time I had done all the benchmarks, I was so sick of swapping cables and rebooting, that I decided not to bother http://www.northernsounds.com/ubb/NonCGI/images/icons/smile.gif


Thus, I almost doubt that upgrading to a GSIF card would solve the problem. (Just a note here, I\'m using an SBLive and haven\'t yet tried GSIF myself...)


Regards,

// Charl




[This message has been edited by cc (edited 06-14-2000).]

[toby]

I have 2 cards: a Montego DirectX card where I get no pops and clicks. However, when I use the Sonorus StudI/O GSIF I get occasional clicks which are not related to polyphony. So far I couldn\'t figure out what the cause of the problem is (The Sonorus drivers are still in Beta), but it\'s definately not the Harddrive nor the CPU.-At least in my case.

[cc]

Hmmn, that could be the beta drivers, but maybe there is some bus contention - is that card using a shared irq?

// Charl

[aab]

hi toby,i am currently using sonorus too, is that possible to email me the gsif driver for testing ? thx a lot

[tonylombardi]

Well, I\'m getting MUCH better performance (all 160 voices, with some effects) without any problem now that I got a GSIF card, the Delta66.
But now I have another problem, which I posted in the software issues category.
Basically I\'m having problems using any more than 256MB of RAM, even though I have 512MB.
If anyone has any ideas, please read my post there and reply.

Thanks!

[toby]

to aab,
I think Sonorus doesn\'t make any secret of their beta drivers.
sonorus.com/beta/lotto.html
user: betapartner, login: bingo