Scope PCI-card effectivity

[garyb]

what's the problem?

all the dsps can be used even with 3 14dsp cards. pci works wonderfully. pci-e is potentially better.

more than traffic problems connecting cards through pci, there are timing issues, hence s/tdm. the pci connection wouldn't allow the cards to access each other directly, there would be controllers in between creating timing issues in a real time environment(as i understand it).

this is such a non issue....

[Inferman]

The problem is - there is suspecting that PCI-slot is too slow to provide enough data-stream between MB and CW card, so as result it will works fine but if You (I mean if I) buy 14 dsp CW card for my current 6 DSP I will not get real 14+6=20 dsp power because PCI bandwidth will cut the real stream so its useless to build 3x14 dsp card system and PCI-e is the only way to get really 20,30,40 dsp power.

Thats why I want to get some tech specification for CW cards but I didnt find it.

[garyb]

if you add cards, YOU WILL GET THE FULL BENEFIT!

many, many users have multiple cards, yet you don't see angry threads about not being able to use them do you?

[Inferman]

But I didnt remember the user who checked this information but still happy.

In article I've read I found such users who was interested why 14+14 DSP doesn't give twice more power than one 14 dsp.
I didnt find this users here but I found them there.

Before Xite release I want to understand is it reasonable to buy 14+14+14 system by low price or it is really better to get Xite with new "honest" wide bandwidth.

[garyb]

i know the article you are speaking of. my client wrote it, but you misunderstand. he had type1 cards along with the newer cards AND his problem wasn't pci bandwidth, it was loading of big devices across cards. Scope has dynamic loading of dsps. it will shuffle devices around to minimize timing issues like when a big device spans several dsps that end up on different cards, which leads to disfunction. in some circumstances, all dsps aren't useable because the load order just doesn't work. still, in that situation Scope offers to reload the dsps to try and find a better order. Pro Tools H/D would just refuse to load the device in that situation. as i said, i have 3 cards including a 15dsp Power Pulsar and i regularly use ALL of my dsp resources.

if you have the money, get the XITE, not becuase it has an "honest" bandwidth, but because it has the equivalent of TEN Scope Professional cards worth of dsp power.

[Tau]

There are more than enough examples of successful 2 and 3 card setups to prove that it works! Admittedly, when you're upgrading, you may feel that 2 15 DSP boards don't have 2x the power of a single one. There may be other factors than PCI bw, like DSP allocation per device, or a limitation to the number of available voices or instances of a device, for example.

I recently had the complete opposite experience: one of my 3 cards gave up, and now that I have only 2, I have the feeling that I can't do half the stuff I did before...

[Fede]

Yes you can believe that it works as expected or email sc for further explanations.

Besides problems of dsp resources allocation/optimizations over more than one dsp which may occur also on a single board, don't get confused:
- the stdm cable (afaik) is mandatory if your setup has more than one card, this is not an issue. With this all the cards work as a single "giant" card with all the dsps on it, a single solid *one* thing system. This is good.
- plugins don't know how many/on which card or dsp they'll be loaded, they see only "one scope thing". The scope os decides it in order to optimize dsp resources. This, again, has nothing to do with pci (because cards communicate among themselves via stdm).
- the pci is used to communicate between the "one scope thing" and the pc host. Yes, it is a bottleneck in the scenario where you are able to load 30 reverbs on the dsps of the "one scope thing" but pci doesn't provide enough bandwidth for all those instances accessing pc memory. In this sense pci-eaters plugins such as reverbs are limited by pci bw, not by number of dsps which instead would handle the demanded load.

So, this is the scheme:

scope plugins <--> scope system (dsps and cards) <--> pci <--> pc resources (memory, asio software interface)


Fede

[Inferman]

Thanx everyone for explanation, I think I've got it