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Other C2 Modem?
- Thread starter JulianL
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I would be shocked if apple came out with a new functionality 1-2 yrs from now and say iphone pro max 18 (some models only) and leave all the confusion to the user
Cant say it wont happen but it would be unusual. But new ceo so who knows.
AeroSatan
macrumors regular
Qualcomm X85 is no slouch believe me. If they put it into the Pro phones, it's because it still offers higher upload/download speeds.
donawalt
Contributor
Check my post number 26, it’s not clear that it’s going to be the X85. There’s evidence that will be the X80. I hope not.
donawalt
Contributor
I asked ChatGPT to compare the X80 and C2, there’s a lot we don’t know about the C2 yet, but here was a complete write up. I don’t think iPhone 18 Pro Max users are going to suffer having the Qualcomm modem. Of course, if it turns out to be the X85, that’s a lot different.
The short version: the Qualcomm Snapdragon X80 is the more capable modem on paper. But I would not conclude that an iPhone 18 Pro Max with the X80 will necessarily have better cellular performance than an iPhone 18 Pro with Apple's C2. Apple appears to have closed a lot of the gap, and the C2 may have meaningful advantages in efficiency and Apple-specific optimization.
And this matters because Apple's current U.S. specifications explicitly identify the C2 in the iPhone 18 Pro, while conspicuously not identifying a modem in the U.S. iPhone 18 Pro Max.
Qualcomm's specifications are substantially more detailed, so the blank C2 boxes shouldn't be interpreted as “C2 can't do it.” Apple simply isn't publishing things like its maximum CA combinations, modulation capabilities or theoretical throughput. Qualcomm says explicitly that X80 supports 6CA sub-6, 10CC mmWave, 1024-QAM, FR1+FR2 CA and peaks of 10/3.5 Gbps.
X80 was Qualcomm's first smartphone modem supporting a six-antenna receive architecture. Qualcomm says this can improve throughput and the amount of data successfully received particularly under weak-signal/cell-edge conditions.
Apple lists the iPhone 18 Pro and Pro Max as 5G with 4×4 MIMO.
That's potentially more meaningful than “10 Gbps versus whatever C2 can do.” Nobody is downloading at 10 Gbps on an iPhone. But maintaining another 50–100 Mbps when you're inside a building, at the edge of a cell, or in a congested environment? That you could actually notice.
Qualcomm also has a very mature RF front end. X80 isn't merely a baseband chip; Qualcomm designed the modem, transceivers, antenna tuning, envelope tracking, RF front end and software as a coordinated system.
That's an area where Qualcomm has accumulated decades of experience.
Apple specifically says C2 provides “AI-powered improvements to cellular quality and reliability.”
That's important because Apple controls an unusually large portion of the system:
A20 Pro → C2 → iOS 27 → power management → thermal management → antennas → physical iPhone design.
That gives Apple opportunities Qualcomm doesn't completely control.
For example, Apple can make decisions about modem sleep/wake states with knowledge of what iOS and the A20 are doing. It can coordinate application traffic, RF activity, thermal limits and battery state. And it can tune the modem firmware against a tiny number of actual devices rather than designing X80 to accommodate dozens of OEM designs.
That integration could make C2 more power-efficient in an iPhone even if X80 is technically the more capable modem.
There are already reports surrounding Apple's launch that C2 improves power consumption versus C1X while adding mmWave and faster uploads.
C2 fixes arguably the biggest hole in Apple's modem program:
C2 supports both sub-6 and mmWave.
So this is the first Apple modem where I wouldn't look at the specification and immediately say, “Qualcomm is clearly preferable.”
Qualcomm still wins the spec-sheet contest, but Apple has reached the point where we need real-world RF testing to know which is better.
So today I'd say X80 is the technically superior modem-RF platform, perhaps 60/40 over C2. Qualcomm has features Apple hasn't demonstrated publicly, particularly 6Rx and very aggressive carrier aggregation.
But I wouldn't use that fact to choose the iPhone 18 Pro Max over the Pro.
In fact, the experiment Apple has accidentally created in the U.S. is fascinating: if teardown confirmation shows that the U.S. 18 Pro Max really has X80 while the U.S. 18 Pro has C2, we're going to have two nearly identical A20 Pro iPhones, on the same carriers and same generation, using competing Apple and Qualcomm modems.
That means within a few weeks we should start getting the tests I actually care about: RSRP/RSRQ/SINR at the same location, cell-edge throughput, handoff behavior, 5G SA behavior, mmWave acquisition, upload performance, idle power consumption, and battery drain during sustained 5G transfers.
Those results will tell us vastly more than 10-Gbps theoretical specifications.
The short version: the Qualcomm Snapdragon X80 is the more capable modem on paper. But I would not conclude that an iPhone 18 Pro Max with the X80 will necessarily have better cellular performance than an iPhone 18 Pro with Apple's C2. Apple appears to have closed a lot of the gap, and the C2 may have meaningful advantages in efficiency and Apple-specific optimization.
And this matters because Apple's current U.S. specifications explicitly identify the C2 in the iPhone 18 Pro, while conspicuously not identifying a modem in the U.S. iPhone 18 Pro Max.
C2 vs. Snapdragon X80
| Capability | Apple C2 | Qualcomm Snapdragon X80 |
|---|---|---|
| Generation | Apple's 2nd-gen modem family | Qualcomm 7th-gen 5G modem-RF |
| 5G SA / NSA | Yes | Yes |
| Sub-6 GHz | Yes | Yes |
| mmWave | Yes — big advance over C1/C1X | Yes |
| 5G Advanced | Apple hasn't published detailed Rel. 18 capability | 3GPP Rel. 18 / 5G-Advanced ready |
| Sub-6 carrier aggregation | Apple hasn't disclosed maximum | 6-carrier CA |
| mmWave aggregation | Apple hasn't disclosed maximum | 10-carrier CA |
| Maximum theoretical DL | Not disclosed | 10 Gbps |
| Maximum theoretical UL | Not disclosed | 3.5 Gbps |
| Modulation | Not fully disclosed | 1024-QAM sub-6 |
| Receive architecture | Apple specifies iPhone as 4×4 MIMO | Up to 6Rx |
| FR1 + FR2 aggregation | Not disclosed | Yes |
| AI modem processing | Yes | Yes, dedicated tensor accelerator |
| Satellite/NTN | Apple supports satellite services at system level | Integrated NB-NTN capability |
| Power optimization | Major Apple emphasis | 5G PowerSave Gen 5 |
| iPhone integration | Potentially exceptional | Excellent, but third-party silicon |
Qualcomm's specifications are substantially more detailed, so the blank C2 boxes shouldn't be interpreted as “C2 can't do it.” Apple simply isn't publishing things like its maximum CA combinations, modulation capabilities or theoretical throughput. Qualcomm says explicitly that X80 supports 6CA sub-6, 10CC mmWave, 1024-QAM, FR1+FR2 CA and peaks of 10/3.5 Gbps.
Where X80 really has an advantage
The most interesting difference to me is 6Rx.X80 was Qualcomm's first smartphone modem supporting a six-antenna receive architecture. Qualcomm says this can improve throughput and the amount of data successfully received particularly under weak-signal/cell-edge conditions.
Apple lists the iPhone 18 Pro and Pro Max as 5G with 4×4 MIMO.
That's potentially more meaningful than “10 Gbps versus whatever C2 can do.” Nobody is downloading at 10 Gbps on an iPhone. But maintaining another 50–100 Mbps when you're inside a building, at the edge of a cell, or in a congested environment? That you could actually notice.
Qualcomm also has a very mature RF front end. X80 isn't merely a baseband chip; Qualcomm designed the modem, transceivers, antenna tuning, envelope tracking, RF front end and software as a coordinated system.
That's an area where Qualcomm has accumulated decades of experience.
But C2 has become genuinely interesting
The C2 isn't simply Apple's answer to “we don't want to buy Qualcomm chips anymore.”Apple specifically says C2 provides “AI-powered improvements to cellular quality and reliability.”
That's important because Apple controls an unusually large portion of the system:
A20 Pro → C2 → iOS 27 → power management → thermal management → antennas → physical iPhone design.
That gives Apple opportunities Qualcomm doesn't completely control.
For example, Apple can make decisions about modem sleep/wake states with knowledge of what iOS and the A20 are doing. It can coordinate application traffic, RF activity, thermal limits and battery state. And it can tune the modem firmware against a tiny number of actual devices rather than designing X80 to accommodate dozens of OEM designs.
That integration could make C2 more power-efficient in an iPhone even if X80 is technically the more capable modem.
There are already reports surrounding Apple's launch that C2 improves power consumption versus C1X while adding mmWave and faster uploads.
There's also a funny reversal here
Remember what made Apple's original C1 interesting: it was extremely power efficient but lacked mmWave.C2 fixes arguably the biggest hole in Apple's modem program:
C2 supports both sub-6 and mmWave.
So this is the first Apple modem where I wouldn't look at the specification and immediately say, “Qualcomm is clearly preferable.”
Qualcomm still wins the spec-sheet contest, but Apple has reached the point where we need real-world RF testing to know which is better.
So which one would I rather have?
For your purposes, I'd score them something like this:| Area | Winner |
|---|---|
| Maximum theoretical capability | 🏆 X80 |
| Carrier aggregation flexibility | 🏆 X80 |
| Weak-signal potential | 🏆 X80, especially 6Rx |
| mmWave maturity | 🏆 X80 |
| Global band/RF flexibility | 🏆 X80 |
| Modem/RF maturity | 🏆 X80 |
| Integration with iPhone silicon | 🏆 C2 |
| Potential power efficiency | 🏆 C2 |
| iOS-aware optimization | 🏆 C2 |
| Real-world reliability | TBD |
| Real-world speed | TBD |
So today I'd say X80 is the technically superior modem-RF platform, perhaps 60/40 over C2. Qualcomm has features Apple hasn't demonstrated publicly, particularly 6Rx and very aggressive carrier aggregation.
But I wouldn't use that fact to choose the iPhone 18 Pro Max over the Pro.
In fact, the experiment Apple has accidentally created in the U.S. is fascinating: if teardown confirmation shows that the U.S. 18 Pro Max really has X80 while the U.S. 18 Pro has C2, we're going to have two nearly identical A20 Pro iPhones, on the same carriers and same generation, using competing Apple and Qualcomm modems.
That means within a few weeks we should start getting the tests I actually care about: RSRP/RSRQ/SINR at the same location, cell-edge throughput, handoff behavior, 5G SA behavior, mmWave acquisition, upload performance, idle power consumption, and battery drain during sustained 5G transfers.
Those results will tell us vastly more than 10-Gbps theoretical specifications.