Discussion How much usablity would this RISC-V CPU w/iDSP have?

whm1974

Diamond Member
Jul 24, 2016
9,460
1,570
96
OK as some of one know I am plan on getting an electronic music keyboard for my birthday next month as mentioned in this:
https://forums.anandtech.com/threads/beginners-music-keyboard.2563249/

As I was learning more about this type of musical instrument, I had a thought on a 64-Bit RISC-V CPU w/ 1 Big core/2 Little cores w/ iGPU and 24-Bit iDSP, clocked at 1,000 Mhz w/ 300Mhz iGPU. Intended for products ranging from music keyboards, synthesizers, basic DAWs, to SBCs and basic low cost PCs.

I'm thinking at least something a serious hobbyist would use for at least for music and low income musicians/producers as well. Although with a wide enough product range that FABs would be willing to produced this. Even if professionals will consider these to be "adult toys".

Or is this getting to be rather silly?
 

Headfoot

Diamond Member
Feb 28, 2008
4,444
641
126
The problem with direct to consumer DSPs is the difficulty in programming them and the lack of a single unfified market to sell into for almost any market entrant. DSPs were widely used during the 90s/2000s on desktop PCs and Macs with ProTools and competitors. Due to the lack of CPU power in those days it was the only way to actually accomplish multitrack editing with effects plugins. This is because, as you know, DSPs are highly specialized but very fast at their specialized tasks. After the multicore era went mainstream, 2011ish, even Avid who was by far the biggest seller of DSP cards direct to consumer has basically stopped development on new DSP cards.

They do still sell them, though I believe they are just sitting on old inventory. Nowadays you can run gobs of realtime plugins easily on a modern multicore CPU. I've got tracks with 10-15 virtual instruments, 6-8 guitar tracks all with amp and cab simulation via Bias FX, plus 2-5 effects plugins (eq's, compressors, that sort of thing) running per track and I haven't even come close to the limit of my overclocked 5820k.

These days if you want to sell DSPs, they have to basically be transparent accelerators that are just a piece of the larger service or product being offered. For example, Fractal Audio sells a hell of a lot of DSPs in their AxeFX line up but they aren't the star of the show - the software they run is. So do Qualcomm, with the DSP integrated in their chip accessible by API for wider processing

The product you propose already exists, and its any low cost x86 APU with a Windows license basically. You'd have to roll together something Raspberry Pi levels of cheap and also support some DAW on it. Hard pill to swallow compared to a el-cheapo $400 laptop with Windows 10 and a $60 Reaper license
 
Last edited:

Headfoot

Diamond Member
Feb 28, 2008
4,444
641
126
I should mention there's of course tons of other weird factors specific to ProTools as well, like their weird obsession with locking down software features into a million different product tiers, some which also required the hardware and some which dont or didnt
 

Nothingness

Platinum Member
Jul 3, 2013
2,371
713
136
Many recent digital synth are just running ARM CPU for doing synthesis. These have become powerful enough to replace older DSP such as Motorola/FreescaleNXP 56k.

Some of these synth are even using plain RaspberryPI with some pro DAC.
 

whm1974

Diamond Member
Jul 24, 2016
9,460
1,570
96
Thanks I was unaware of modern CPUs and SOCs have gotten powerful enough to replace DSPs for some applications. However don't some professional level sound cards have DSPs?
 

Nothingness

Platinum Member
Jul 3, 2013
2,371
713
136
I guess high-end DSP are still competitive, but I think in many cases their use is due to legacy code.

EDIT : BTW some synths are now using FPGA for parts or all of sound synthesis.
 

whm1974

Diamond Member
Jul 24, 2016
9,460
1,570
96
I guess high-end DSP are still competitive, but I think in many cases their use is due to legacy code.

EDIT : BTW some synths are now using FPGA for parts or all of sound synthesis.
I thought that one of the advantages of DSPs over CPUs, was the much lower power consumption and lower TDP?
 

Thala

Golden Member
Nov 12, 2014
1,355
653
136
I thought that one of the advantages of DSPs over CPUs, was the much lower power consumption and lower TDP?

Considering that a high-end ARM core like the Cortex A76 consumes less than a watt, there is not much benefit in even lower power consumption for many applications.
 

Mopetar

Diamond Member
Jan 31, 2011
7,797
5,899
136
I thought that one of the advantages of DSPs over CPUs, was the much lower power consumption and lower TDP?

Sure they'll be more efficient for the same reason that dedicated special purpose hardware is often faster as well. It doesn't need to deal with anything other than the special purpose it was designed for, but it's the same case where general purpose CPUs offer good enough results. Hell, AMDs next server/HEDT chips are going to pack 64C/128T into a 250W TDP envelope, which is slightly more than the TDP of an FX-9590 which only had 8 threads across 4/8 cores. Sure it was clocked a hell of a lot higher, but IPC improvements will make up for a good chunk of that.

Better has a difficult time competing against good enough.
 

whm1974

Diamond Member
Jul 24, 2016
9,460
1,570
96
Sure they'll be more efficient for the same reason that dedicated special purpose hardware is often faster as well. It doesn't need to deal with anything other than the special purpose it was designed for, but it's the same case where general purpose CPUs offer good enough results. Hell, AMDs next server/HEDT chips are going to pack 64C/128T into a 250W TDP envelope, which is slightly more than the TDP of an FX-9590 which only had 8 threads across 4/8 cores. Sure it was clocked a hell of a lot higher, but IPC improvements will make up for a good chunk of that.

Better has a difficult time competing against good enough.
Come to think of it, this wouldn't be very useful now days due to only having one big core and two little ones, and with no SMT.

Wouldn't most applications need quad cores anyway?
 

Nothingness

Platinum Member
Jul 3, 2013
2,371
713
136
Come to think of it, this wouldn't be very useful now days due to only having one big core and two little ones, and with no SMT.

Wouldn't most applications need quad cores anyway?
For synth apps, polyphony will mostly scale linearly with the number of cores :)

But it's impressive what you can already do with rather limited performance. As an example the Access Virus Ti2 is being run by a 8051 controlling 2 DSP 56321 at 275 MHz, and this can easily exceed 16 voices (up to 90 for simple patches according to Access).
 
Mar 11, 2004
23,031
5,495
146
Thanks I was unaware of modern CPUs and SOCs have gotten powerful enough to replace DSPs for some applications. However don't some professional level sound cards have DSPs?

I think that's more because its required for consistency to their past high end products, or is due to some vintage aspect (which has become a big thing in the audio world, after companies saw people rebuilding their old gear instead of buying newer). I might be wrong though.

But Creative has dropped their DSPs (they use just like a 4 core SIMD solution to run their software stack; I'm not sure that they've fully ported all the capability of their older stuff though - but its stuff that they can't easily work with modern games so there's not a lot of reason to). I believe AMD does something similar (has a SIMD block onboard, maybe included in the video processing block?) that they used for TrueAudio (which hasn't really taken off on PC even though I believe its still there and they even touted it for some audio stuff in like the past couple of years), but that has been used on consoles (and I believe was maybe the impetus behind them developing it). It might've only been Sony (and not sure its used for all audio processing even then now) as I believe Microsoft put their own solution in it (which let them add newer audio format support like Dolby Atmos).

Chord actually has now even developed an FPGA DAC (as in they use the FPGA instead of a standard DAC chip). I'm not sure what process tech most DACs were made on but I noticed the Sabre DAC chips used on some newer Creative product looked tiny, like 1/4 or smaller of the size of the typical DAC chips I'm used to seeing. I don't know if that factored into Chord's decision though, I think its more just simply it lets them add features and possibly fix issues that otherwise might have needed reworking the schematic and changing chips. And I think it lets them do more UI type stuff (they have some weird colored buttons that change depending on what you're playing back).

Which there's been a movement for back to R2R/ladder DACs, which makes sense if you know audiophiles and their weird desire for senseless complexity so they can pretend its superior just because it gives

Korg has some DSD DACs on PC and converts PCM audio to DSD using software (which I believe some DAC chips have the capability to convert one to the other). iFi supposedly somehow programmed the DAC chip of some lower level Burr-Brown chip to do DSD processing in their iDSD (there was a small fuss made when some sound engineer that works in DSD audio was skeptical as the DAC chip they used, according to the spec sheet didn't have the capability they advertised, but they assured him it would actually work and he tested and found it worked).

The Realtek chips that are standard on PC these days (ALC 1220 I think is the common high end one these days) do audio processing and DAC, but you can use it for just one (there's some boards that do that and pair it with an ESS Sabre DAC). And many mobile SoCs have their own built in (but its been awhile since I've seen much analysis of that, I don't recall if people took apart the USB-C headphone adapters to see if they had DACs built in or if they were just doing analog out, which I believe Apple does on the lightning headphone adapters for iPhone - it can do digital out to a DAC as well but I think theirs just does audio out - which led many people to wonder why Apple did that with some guy going so far as to physically hack in a 3.5mm jack onto his iPhone).

Not entirely sure what my point is with posting all of that other than remarking about odd audio stuff these days.
 

NTMBK

Lifer
Nov 14, 2011
10,208
4,940
136
@Nothingness @darkswordsman17 Thanks for the info. Now I'm thinking that once I get far enough where I start writing my own music, I will need a external sound card or is my on board audio good enough?

You're overplanning this :) Just grab a cheapo Casio keyboard and start writing. Just do it. Don't sit on forums discussing minutiae of hardware details. Just start, right now! Go! Play some notes, screw around with melodies and rhythms!
 
  • Like
Reactions: Nothingness

whm1974

Diamond Member
Jul 24, 2016
9,460
1,570
96
You're overplanning this :) Just grab a cheapo Casio keyboard and start writing. Just do it. Don't sit on forums discussing minutiae of hardware details. Just start, right now! Go! Play some notes, screw around with melodies and rhythms!
At this point I need to learn how to play the keyboard before I can start writing music using it. And beside I wont be able get one until next month at the earliest. Once I get this and stop posting, well you guy would know happen to me...:p
 
  • Like
Reactions: NTMBK
May 11, 2008
19,303
1,129
126
It is not strange that most use arm more for audio processing. The more modern ARM cpu blocks have the NEON unit. A SIMD unit.
The raspberry pi 3 has neon units (64bit floationg point support) and dsp instructions and being a quad core.
And the more modern arm cores and almost all cortex m4 models for embedded use (depending on the manufacturer that has aquired a license and have their specific implementations) have advanced dsp instructions as part of the standard instruction set.