You can’t have it all with DSD native processing either. The signal needs to be re-modulated to one bit after, as the signal path shows. It’s just the rate at which DSP is done that is different.
I’m interested to know if new M1max processor would solve the congestion issue over the 2018 intel, since RAM is useless for Roon, my 64 GB did nothing and it looks like 4.5 GHz in 6 cores were resulting with 0.7/0.8 process speed, so rest of cores are a waste too.
- RAM size is not really that important for DSP. RAM speed helps.
- In your case, it’s actually 4.5GHz in 2 cores.
- DSD256 works at 11.3 megahertz. That’s 32 times 352.8kHz. For that kind of rate, you’d need GPU support.
- You can turn off native DSD processing, leave the preset on, and tell Roon to send DSD256 to the DAC.
Your assertion about speed isn’t exactly true. To work out the data load you multiply bit rate by bit depth. So 384/32 is actually the same data load as DSD256. The CPU support is needed because of the conversion processes between the formats.
DSP is done in “PCM domain”, using 32- or 64bit samples, even for DSD. After DSP, there’s a delta-sigma modulation step to re-quantize to 1 bit and get back to “DSD domain”.
No, Marian is right. Bit depth is basically irrelevant with 64 bit floating point math. Precision for almost any bit depth is available in abundance. But sample rate is relevant because each sample arithmetic is a floating point operation.
AJ
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We may be at crossed purposes. Conversion from PCM to DSD is processor intensive but the simple act of streaming DSD is no more demanding than the same number of bits of PCM, despite the difference in sampling frequency. Happy to roll back if I got it that[quote=“WiWavelength, post:26, topic:217891, full:true”]
No, Marian is right. Bit depth is basically irrelevant with 64 bit floating point math. Precision for almost any bit depth is available in abundance. But sample rate is relevant because each sample arithmetic is a floating point operation.
AJ
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Streaming-wise, you’re right, bitrate is all that matters. But the question here was why native DSD processing required so much more CPU than 352.8kHz PCM. When DSP is involved, sampling rate ratio is all that matters.
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This is a good wakeup call for me, thinking RAM was the most important part of the equation, and not knowing how ROON interfaces with processor. For sure, I need to replace the weak link of this system, the mac mini. I saw several discussions about computer requirements in here but all still grey to me. If the goal is to play DSD 256 and 512 without conversion, since I have the files and DAC, then is their a machine (mac, windows, linux) that can support ROON demand for all the presets of DSP, or there’s no such thing in the current market and I need to wait? I know the size of the library is important in ROON, which I didn’t pay attention to since I’m always hungry for more of good music, it might be better to have a few ssd hard drives and plugging them in and off into ROON like playing vinyl. I saw that Apple has the mac studio with M1 max processor, would that work, or the M1 ultra is the one, which is $1300 more? I know there are machines dedicated for ROON playing with more efficiency than computers, but they have to allow USB-C (thunderbolt 3/4) connection to plug in external ssd drives and DAC’s that use USB-C, such as Burson Conductor, before being considered.
Thank you all for the good eye-opener information.
The great thing about apple is that you have 14 days to return if you are not happy with the solution…that’s a huge benefit. The M1 and M2 chips are incredible. That is if you order or buy at at an apple shop, resellers not so sure this applies.
Keep in mind that if you use DSP, you are basically converting to PCM and back anyway; the signal path disguises that a little. Once again, I don’t think you need native DSD processing. If it works without it, you can keep the profile, send DSD to the DAC and also keep your machine.
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