Asymmetric Quantization: Near-Lossless Retrieval with 97% Storage Reduction

7/2/2026 at 2:12:30 PM

``` We evaluated several precision pairings across our internal retrieval benchmark suite. Scores are NDCG@10 averaged across the suite, scaled to 0–100. NDCG@10 (Normalized Discounted Cumulative Gain at rank 10) measures how well the top 10 results are ordered against the ideal ranking, rewarding relevant documents more when they appear higher, with 100 being a perfect ranking. The full-precision baseline averages 90.26. Int8 query against binary documents averages 89.65, a 0.61 point drop, while reducing document-vector storage by 32x ```

Saying "Near lossless" to mean 90% accurate retrieval of saved vectors is simply a lie. Lossy-ness is binary, not something you can paper over with getting close enough. And 90% is not close. Sure, LLMs are all about gradient descent on noisy data sets so I guess this is acceptable in this field but that terminology usage still bothered me

by Zagreus2142

7/2/2026 at 2:35:15 PM

I don't believe that's what they were saying at all though. The claim appears to be that it's near lossless relative to their own baseline that uses float. Which I'd grant, since a 32x storage reduction for 0.61% loss in quality is a reasonable trade off when you've already decided to accept that ~90% is "good enough".

by kittoes

7/2/2026 at 7:32:20 PM

Yeah, what bugs me about stuff like that is like they spend all this time and then they output several or minimal real testing to prove the theory It's like you're building your model to And just because it takes a long time to compute and do the testing, you'd rather publish your article and then try to get credit on something that hasn't really been proven. Look, prove your results. Study it. Ruggedize it. Make sure it works. Then, show us.

by theropost

7/2/2026 at 2:58:01 PM

near lossless refers to being 89.65/90.26 = 99.32% of baseline, i'm pretty sure.

by seritools

7/2/2026 at 3:35:06 PM

yes exactly.

by breadislove

7/2/2026 at 11:10:47 AM

I would love to see real examples of what reduced quality means in practice. Are you able to recover a document from the vector in a human readable format? If so, what sort of changes come up?

I could imagine a scenario where differences tend to be more substantive than you'd expect because of how less frequent words with fine distinctions in meaning - the very words that make the document special - may be embedded in the vector space.

by elil17

7/2/2026 at 12:16:31 PM

Most of the fine distinctions are already lost when a document is processed through a pile of linear algebra to turn it into a fixed-size list of floating-point numbers, as you can see from the NDCG@10. Vector search is not a tool for fine distinctions. It's a tool for reducing a large pile of documents to a smaller selection of candidates, which you can then check individually with some more expensive method.

by yorwba

7/2/2026 at 3:44:13 PM

The ndcg loss is minimal 90.26 -> 89.65. This means it maintains most of the quality.

by breadislove

7/2/2026 at 3:36:23 PM

this is the reason why we report ndcg and not recall. ndcg respects fine grained details so you get the an overview of how much details you are trading off since it would hurt the ranking.

by breadislove

7/2/2026 at 11:00:38 AM

Hey breadislove; amazing article, I’ll be sending mixedbread an email in the morning that may interest you (email will be <5-characters>@pm.me)

I have also been working in compression and performance engineering, and managed to get a 99+% compression unlock versus conventional approaches (100+KB down to 1KB) in the scenario of 30 minute massive multiplayer game replays for a “game+engine” I’m developing

I think there’s a synergy between these 2 concepts I’d love to chat some more

by purple-leafy

7/2/2026 at 2:07:05 PM

Any way I can read about this or the use case? I have a hobby interest

by palinnilap

7/2/2026 at 7:07:31 PM

Yes soon I’ll be launching my game and engine, and will have a blog post - just keep an eye on Show HN over the following week

by purple-leafy

7/2/2026 at 3:37:28 PM

to which email did you send it? can u send it to support please?

by breadislove

7/2/2026 at 7:16:48 PM

Sent to the support email with the subject line “Hackernews …”

by purple-leafy

7/2/2026 at 4:27:12 PM

Asymmetry is clever. FWIW, this is very similar to the strategy employed by BitNet models (i.e., int8 activations with binary or ternary weights); I suspect retrieval is a little more amenable to this approach.

In principle, binary x binary should be pretty fast since it just requires bitwise XNOR and popcount/reduction, but in practice it's slow unless you've really optimized it. And, as stated in the article, you'd still be losing a lot of accuracy that way.

by derrickquinn

7/2/2026 at 2:19:03 PM

To people smarter than me, how impressive and/or revolutionary is this?

by kaizenite

7/2/2026 at 1:41:44 PM

If you squint hard enough, it sounds like their storage layer is a bloom filter

by alfiedotwtf

7/2/2026 at 11:29:39 AM

there is no such thing as "near lossless"

by functionmouse

7/2/2026 at 11:52:22 AM

There is, after you define what you’re ready to loose and understand the lossy space. That’s how we came up with mobile cellphones, audio and video codecs etc. Literally powering all modern devices we use.

by ttoinou

7/2/2026 at 2:21:25 PM

So then ... "lossy"

by greenleafone7

7/2/2026 at 4:39:06 PM

theres a big difference between 99% quality and 30%. near lossless is a good name for the first one. if you treat it in a binary way where everything short of 100 falls into one "lossy" bucket you lose all the practical differences that make one encoding much better than another.

by tancop

7/2/2026 at 7:17:03 PM

I agree with you somewhat, and I like what is described in the article. But I also feel like we are diluting the meaning of the word to make things sound better. Lossy/Lossless is inherently binary, and it carries a specific meaning. It would not detract from the work at all if it was described differently.

You can't be a little bit on fire :)

by greenleafone7

7/2/2026 at 5:36:13 PM

> theres a big difference between 99% quality and 30%.

sure

> if you treat it in a binary way where everything short of 100 falls into one "lossy" bucket you lose all the practical differences that make one encoding much better than another.

no; lossless is an inherently binary term. and I don't lose all the practical differences of better lossy encoders by understanding that; I'm not just going to start using mp3 96k because I have an understanding of lossless vs lossy encoders...

Lossless is an objectively binary term.

by functionmouse

7/2/2026 at 8:05:26 PM

Lossless is objective for information theory. To get from the real world to digital world you need an analog to digital converter, this process is by definition lossy. We are interested in the real world, and information is pure but never represents exactly reality.

Lossyness is baked into our problem statement here.

Using terms like near lossless means we think we are very close to reality for what we’re trying to do

by ttoinou

7/2/2026 at 1:35:18 PM

Actually, all of those things are considered "lossy".

by functionmouse

7/2/2026 at 2:37:42 PM

Yes, anything not lossless is lossy. Near-lossless is not lossless, so it is lossy. I hope we speak the same language

by ttoinou

7/2/2026 at 10:28:17 AM

The Pi compression algorithm is better.

by rq1

7/2/2026 at 1:25:46 PM

Doubtful. The problem with the pi idea is that you need to include the offset, which will likely be as long as or longer than your data.

by luma

7/2/2026 at 12:55:32 PM

" A single document produces more then one embedding, depending on the complexity of the document it can produce hundreds or thousands of vectors."

That typo up there is kind of endearing in the AI slop era.

by nathan_compton

7/2/2026 at 3:23:21 PM

Not seeing a typo in your quote. Can you point it out?

by HenryMulligan

7/2/2026 at 3:50:52 PM

I think they're referring to "then" vs "than"

by thatspartan

7/2/2026 at 4:01:13 PM

ah whoops, I'll fix it. ty!

by breadislove

7/2/2026 at 5:35:14 PM

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by vasylvd

7/2/2026 at 5:20:27 PM

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by dismissed181

7/2/2026 at 12:41:45 PM

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by m_m_carvalho

7/2/2026 at 9:00:24 AM

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by mv_d5339e31

7/2/2026 at 7:59:33 AM

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by johnathan101

6/30/2026 at 11:58:34 PM

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by TradingReality

7/2/2026 at 8:48:15 AM

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by Ameo

7/2/2026 at 3:28:07 PM

Unfortunately as cost reduction trends to 100%, it comes along with an intrinsic high-pass sarcasm filter.

by mwigdahl

7/2/2026 at 9:49:25 AM

Reminds me of 'Learning to be me' by Greg Egan

by peheje

7/2/2026 at 12:00:11 PM

You would obviously be trading storage for compute and time to retrieve the storage.

by throwaway2027

7/2/2026 at 9:48:42 AM

100% reduction is impossible for something which should work, because -100% means it is now 0

by throwaw12

7/2/2026 at 9:55:31 AM

They were clearly being sarcastic

by neonstatic