tekacs
5 hours ago
I'm pretty baffled by their choice of axes. I would have thought that the left was the cheapest, not the most expensive. I appreciate that this layout means that top right can be best, but it's still unintuitive to have this backwards cost axis IMO.
Putting that aside, I spend all day every day implementing very, very hard things right on the edge of what agents are (barely, sometimes) capable of, and I have had to keep Opus on max for things that need 'real validation' for a while now. And that has felt like 'the only way' to get Opus to perform even close to 5.5 xhigh. I'm only using Opus at all because GPT-5.5 in the subscriptions only has a small (400k, but 258k effective) context window.
The difference is that 5.5 xhigh is extremely fast in most practical cases, both efficiently implementing _overall_, and responding very quickly with great adaptive thinking if you ask it something that it doesn't have to think about. Opus 4.8 Max will needlessly chew on everything and can take hours to implement even simple things, so I can mostly only use it for planning/review.
Fable is much much better at adaptive thinking / responding quickly (although probably still worse than 5.5 xhigh), and... I think folks have said enough elsewhere about its strengths and weaknesses. Sadly still not a reliable implementor for my hard tasks though (that's still GPT's domain) – it tends to leave big, dangerous holes hiding inside implementations unless babied.
budsniffer952
an hour ago
>Putting that aside, I spend all day every day implementing very, very hard things right on the edge of what agents are (barely, sometimes) capable of
Is a single thing in your post demonstrable, or are we just supposed to take your word for it? Because all of this stuff sounds laughably subjective.
mklarmann
3 hours ago
It’s Gartner. Top-right is where you want to be.
0123456789ABCDE
2 hours ago
gartner magic quadrant charts don't break the natural expectation of left-to-right, and bottom-to-top, increasing values, this charts from cursor post do.
arcanemachiner
2 hours ago
Sounds like you're in the Trough of Disillusionment.
pbowyer
4 hours ago
> I'm only using Opus at all because GPT-5.5 in the subscriptions only has a small (400k, but 258k effective) context window.
Do you find that makes a difference in your work? I've been using 5.5 high/xhigh to optimize and benchmark a C codebase, and just reading the initial code virtually fills the first context window. A session will auto-compact 5-15 times, but it seems to do okay in spite of that because the task is mainly focused on the latest window each time.
I think for programming the strength of GPT over Opus is winning here over the context window.
tekacs
a few seconds ago
> I think for programming the strength of GPT over Opus is winning here over the context window.
On this, absolutely!
I more often use Opus for planning than for implementation. In those cases I really do need the very large context window, because the agent has to read in a bunch of my code base and a bunch of previous plan files and product context and such, to understand what we're talking about.
And then I need to go back and forth with it over a really extended period: getting into a bunch of details, asking it to load how things already work so that we can discuss options for evolution of those, etc.
For that kind of thing, compaction completely destroys its effectiveness because even if you try to serialize out all the decisions made in the conversation into a plan file, the agent still loses e.g. the plan files and code files that it's read in that are adding sharp edges to its understanding of the scope of what's being planned.
For implementation or something like what you're describing in the vein of benchmarking, often I can get away with compaction. Although even then, if the agent needs to have a lot "loaded" into its head, to implement something very, very subtle and complex, in those cases it can be really detrimental if it compacts.
cherryteastain
3 hours ago
You can set GPT 5.5 to 1M context mode in Cursor but it costs more after the default 272k.
tekacs
2 hours ago
Yeah I've done this, it's just unaffordably/impractically expensive compared to the official subscriptions :/
0123456789ABCDE
3 hours ago
opus@max is on average worst than opux@xhigh
for supporting evidence, see first chart here: https://www.anthropic.com/news/claude-fable-5-mythos-5