Processors/Comparison
15 specifications
Intel Core i7-1255U vs AMD Ryzen 9 8945HS
On paper, the Intel Core i7-1255U has more cores (10 against 8), the AMD Ryzen 9 8945HS boosts higher, and the AMD Ryzen 9 8945HS carries more L3 cache. Specifications describe what each chip is designed to do; how much of that either one holds under continuous load is a separate question.
Intel Core i7-1255U
Intel · Alder Lake-U (12th Gen Core) · Laptop
AMD Ryzen 9 8945HS
AMD · Ryzen 8040 (Hawk Point, Zen 4) · Laptop
Cores and clocks
Cache and power
Platform
A check marks the higher figure only on rows where higher is unambiguously better. Rows without one are not ties; they are specifications where “better” has no meaning.
Reading the table
What the difference means.
Cores and threads
This pair splits: the Core i7-1255U has more cores (10 against 8) while the Ryzen 9 8945HS runs more threads (16 against 12). That happens when one design runs two threads on every core and the other does not, or mixes large and small cores. A second thread on a core adds roughly a quarter to a third of a core's work, not a whole one, so 10 full cores and 16 threads on 8 cores land closer together than either number suggests. Work that spreads across everything, such as rendering, compiling and video export, is where the difference shows; which side wins it depends on how fast each core is, which a specification sheet does not say.
Boost clock
The Ryzen 9 8945HS boosts to 5.2 GHz against 4.7 GHz, 11 percent higher. Across generations it is not a guide to speed on its own, for the reason above. Boost is also a peak: it is held for seconds to minutes, on one or two cores, while the cooling and the power limit allow. What either chip settles at under a long load is lower, and it depends on the cooler and the motherboard as much as the chip.
Cache
The Ryzen 9 8945HS carries 16 MB of L3 cache against 12 MB. Cache is fast memory on the chip, and a larger one means the cores wait on main memory less often. Games, large spreadsheets and compiling respond to it; rendering and video export, which stream through data in order, respond much less.
Power and cooling
The Ryzen 9 8945HS is rated at 45 W against 15 W. The rating is the heat the cooler has to move for the chip to hold its speed, and modern chips draw well above it in short bursts. In a laptop the maker chooses the real limit inside a range, so the same chip can behave like two different processors in two machines. That spread is what a sustained test measures and a specification sheet cannot. A chip whose cooling falls short does not fail. It slows down, and it does so after the first minute, which is why short benchmarks miss it.
Platform
Laptop processors are soldered to the board, so this is a choice between machines, not between chips you can swap. What differs between two laptops with these parts is mostly the power limit and the cooling the maker gave each one.
Which to pick, on paper
- Rendering, compiling, video export
- Ryzen 9 8945HS
- 16 threads against 12. Work that uses every thread scales with how many there are.
- A quiet or compact build
- Core i7-1255U
- 15 W against 45 W: less heat to move, so a smaller cooler and slower fans.
What no table says
How much of its speed a processor keeps after the first minute depends on the cooling and the power limit of the machine it is in. If you own one of these, measure it: the test is free and runs in this browser.
Questions
- Is the Core i7-1255U better than the Ryzen 9 8945HS?
- By need, on the specifications: rendering, compiling, video export: the Ryzen 9 8945HS; a quiet or compact build: the Core i7-1255U. No specification says how much speed either one keeps under a long load; that depends on the cooling and the power limit of the machine it is in, and it is what a sustained test measures.
- Do the Core i7-1255U and the Ryzen 9 8945HS use the same socket?
- Laptop processors are soldered in place, so neither can be swapped for the other.
- Does the Core i7-1255U or the Ryzen 9 8945HS have integrated graphics?
- Both do: Intel Iris Xe Graphics (96 EU) on the Core i7-1255U and AMD Radeon 780M on the Ryzen 9 8945HS.
- Which runs hotter, the Core i7-1255U or the Ryzen 9 8945HS?
- The Ryzen 9 8945HS is rated at 45 W against 15 W, so it produces more heat under load and needs the larger cooler. How hot either one actually runs depends on the cooler and the case more than on the chip.
More comparisons
- Intel Core i7-1255U vs AMD Ryzen AI Max 385
- Intel Core i7-1255U vs Intel Core i5-1235U
- Intel Core i7-1255U vs Intel Core i5-14450HX
- Intel Core i7-1255U vs AMD Ryzen 9 270
- Intel Core i7-1255U vs AMD Ryzen 9 7940HS
- AMD Ryzen 9 8945HS vs AMD Ryzen 9 270
- AMD Ryzen 9 8945HS vs AMD Ryzen 9 7940HS
- AMD Ryzen 9 8945HS vs Intel Core i5-1235U
- AMD Ryzen 9 8945HS vs AMD Ryzen 7 260
- AMD Ryzen 9 8945HS vs AMD Ryzen 7 7840HS
- AMD Ryzen 9 8945HS vs AMD Ryzen 7 8840U
Every figure on this table is a design target. None of it is a measurement.
Nothing above describes how a processor behaves twenty minutes into a sustained workload, which is where two chips with nearly identical specifications routinely diverge. A boost clock is a ceiling the vendor permits, not a rate the chip sustains, and whether it holds depends on the cooling, the case, the power profile and the room. None of those appear on a specification sheet.
We deliberately do not reduce these figures to a single score. A composite invented from specifications would look authoritative and measure nothing, and choosing the weights would be choosing the winner.