As for the HP DAC..
I have a HP Probook 6570b which I'm pretty sure has the same DAC as the HP laptop tested by Amir, and just compared it to my Anedio D2 DAC and the difference is absolutely huge.
I did this "subjective" test on a pair of JBL LSR305P mkII listening distance 1m in a big room partly treated with absorbers around my listening position (building a studio here but not yet finished though my listening postition is now mostly free from any direct reflections).
I don't consider the LSR305P to be good speakers for resolving finer details, they have their own "grainy/distortion" thing going on which is especially apparent when listening nearfield with enough absorption. But apparently the faults in the HP DAC are big enough to be very audible.
My subjective experience is that relative to the Anedio D2 the sound becomes more "closed", it's hard to believe they both have a flat frequency response as the HP DAC doesn't "sound" flat, it sounds a bit muddy in the upper/mid bass, and the highest treble seems lacking / less airy. With songs that push the treble it's quite a difference, the HP DAC sounds distorted in parts of the treble. For instance I put on a commercial song 'Martin Garrix - High on life' (always put a few hit songs in my test playlist usually for listening to frequency balance, you'd be surprised how many "hi-end hifi" setups can't even properly reproduce commercial hitsongs because their freq balance is all off and then blame the songs lol) and the HP DAC messes it up big time. When the loud synth melody comes in at around 1:15 the Anedio D2 does it very smoothly and makes clearly audible the synth sound and its noise aspect, but with the HP DAC this same synth sound is not smooth at all but "grainy" and part of the synth sound and part of the noise aspect of that sound are not resolved but instead you hear it as distortion. In total the synth sound and noise sound and distortion added together kinda give the same frequency / amplitude as the Anedio D2 does, except with the Anedio D2 it's all resolved and smooth as hell.
Now I'm not imagining things here or have "super ears" or whatever. This is surely audible to anybody with working ears who is pointed out what to listen for (under my listening circumstances, all bets are off when people do a listening test in a reverberant room non nearfield etc which will almost always hide certain details).
So I'm surprised the HP DAC still scores a Sinad of 87dB! It makes me think yet again that with a DAC distortion can hide in sneaky corners from measurements.. Surely the distortion I'm hearing in the example I gave is not 87dB down. It's a song with virtually no dynamic range, for me to be able to hear this distortion this clearly means it's more like -10dB or something with that particular sound. I keep getting the feeling that DACs often manage to do something wrong which isn't normal harmonic distortion or intermodulation distortion. This just doesn't feel like the disortion from an amp or speaker. It's something to do with information that's not being resolved.. SRC errors or something? Or some form of jitter which doesn't show up equally distributed but very audible in certain ways at specific points? What can it be?