Efficiency Cores on Trial: Dimensity 9500 vs Exynos 2600

In the space of just a few years, smartphone chips have gone from chasing raw horsepower to questioning whether some of that horsepower is even necessary.

Nothing captures this shift better than MediaTek’s bold decision to rip out traditional efficiency cores from its flagship designs, starting with the Dimensity 9300 and now refined in the Dimensity 9500. That move didn’t just surprise the industry – it challenged a decade of received wisdom built around big.LITTLE layouts and tiny “little” cores babysitting your emails and notifications.

Fast forward to late 2025, and the results are hard to ignore. The Dimensity 9500 now trades blows with Qualcomm’s Snapdragon 8 Elite Gen 5 at the very top of the Android food chain, often edging ahead in AnTuTu 10 while staying highly competitive in Geekbench 6. At the same time, Samsung’s Exynos line is still clinging to efficiency cores in its high-end designs, even as the upcoming Exynos 2600 shows that its 2nm GAA process is finally good enough to play with the big boys on efficiency without needing so many “training wheels.”

This raises an uncomfortable question for Samsung in particular: in an era of ultra-efficient nodes and smart schedulers, are classic efficiency cores still earning their silicon, or are they quietly holding back what Exynos could have been?

How We Got Here: From big.LITTLE to “All Big” Experiments

For years, ARM-based mobile chips followed a familiar blueprint. You had a small cluster of low-power efficiency cores to handle background tasks and light apps, and a handful of big performance cores that woke up when you launched a 3D game or crunched through a heavy photo edit. Qualcomm’s Snapdragon 8 Elite Gen 3 was a textbook example of this era: a 1+3+2+2 layout built around one Cortex-X4, several Cortex-A720 mid cores, and a pair of tiny Cortex-A520 efficiency cores quietly sipping power in the background.

But then MediaTek flipped the table. The Dimensity 9300 arrived in 2023 with no dedicated efficiency cores at all, and Qualcomm followed a year later with the Snapdragon 8 Elite (Gen 4), moving to its custom Oryon CPU cluster with only high- and medium-performance cores. Qualcomm even argued that heavily optimized, higher-frequency cores on a modern node could match or beat classic “little” cores in light tasks while retaining the ability to ramp up for demanding workloads – making the old efficiency cluster feel redundant.

That was more than a spec sheet tweak; it was a philosophical pivot. Instead of carving up the CPU into big, middle and tiny cores, the new idea was to rely on a smaller number of flexible, efficient cores that could scale up and down as needed. MediaTek, traditionally lumped in with Samsung’s Exynos as a second-tier option, suddenly looked like a trendsetter.

Dimensity 9500: Proof That the Gamble Paid Off

The Dimensity 9500 is essentially the second generation of MediaTek’s bet on “all big” style designs, and the specs show just how committed the company is to that philosophy. Its 8-core CPU features one ARM C1-Ultra core at 4.21 GHz with 2 MB of L2 cache, three C1-Premium cores at 3.50 GHz with 1 MB of L2 cache each, and four C1-Pro cores at 2.70 GHz that act as the lower-clocked workhorses.

On paper, that looks like overkill. In practice, it has elevated MediaTek from “budget-friendly alternative” to a genuine flagship contender. The Dimensity 9500 posts higher AnTuTu 10 scores than the Snapdragon 8 Elite Gen 5, and while the gap in Geekbench 6 is smaller, it’s clear that MediaTek is no longer just playing catch-up. It is defining one side of the high-end philosophy: simplify the core mix, clock everything high, and let the process node plus clever power management do the heavy lifting on efficiency.

Of course, this approach isn’t free of drawbacks. Running only large and mid-sized cores means you’re leaning hard on thermal headroom and scheduling logic. Push too far, and your chip will throttle quickly under sustained loads, which is exactly the sort of behavior that has made some users suspicious of MediaTek in the past and skeptical of synthetic benchmarks in general. Still, from a pure silicon story, the Dimensity 9500 proves that top-tier Android performance no longer requires a classic efficiency cluster.

Exynos 2500: When Efficiency Cores Become a Crutch

Now look at Samsung’s Exynos 2500, unveiled earlier in 2025. On paper it stuck more closely to tradition, keeping efficiency cores in play while trying to juggle performance, thermals, and yields on a shaky 3nm node. In reality, that strategy backfired. The Exynos 2500 struggled with low yields and thermal stability problems, and its performance gap against rival flagships felt far larger than the launch dates would suggest.

Efficiency cores didn’t save Samsung here. If anything, they became a psychological crutch – a way to feel safer about thermals instead of confronting the real issue: the node just wasn’t ready, and the architecture was split between too many middling cores doing too little. Exynos has carried the stigma of aggressive throttling for years, and Samsung’s instinctive response seems to be, “Add more efficiency cores and keep clocks conservative so we don’t get roasted again.” That’s understandable, but it’s also how you end up shipping a flagship chip that looks conservative and underwhelming in 2025.

The irony is that the problem with Exynos 2500 was never that it had efficiency cores at all – it was that it had them on a node that simply didn’t deliver, wrapped in a design that felt compromised from every angle. It was a chip engineered around fear of failure rather than confidence in the silicon.

Exynos 2600: A Huge Step Forward – With One Foot on the Brake

The good news for Samsung is that the Exynos 2600 already looks dramatically better. Built on the 2nm GAA process, early reports point to around 30 percent gains in efficiency and thermal behavior, plus a significantly upgraded NPU aimed squarely at on-device AI. And in leaked Geekbench 6 runs from reputable sources, the Exynos 2600 is no slouch: a single-core score around 3,455 more or less matches the Dimensity 9500, while a multi-core score of 11,621 actually pulls ahead.

Those numbers are especially interesting once you remember that the Exynos 2600 still carries dedicated efficiency cores. In other words, Samsung is hitting Dimensity 9500–class CPU performance with one hand tied behind its back. If engineers had gone all-in on high- and mid-performance cores, trusting the 2nm node and modern power management, Exynos 2600 could have been the chapter where Samsung finally broke out of Qualcomm’s shadow instead of merely catching up.

That conservatism has a real price. Because Exynos still isn’t trusted to power Samsung’s global flagships alone, the company is projected to spend around $4 billion sourcing Snapdragon 8 Elite Gen 5 chips for the Galaxy S26 Ultra. That’s a massive bill, and a big part of it comes from Exynos failing to inspire the confidence that MediaTek has managed to build with its Dimensity line.

Do Efficiency Cores Still Matter in Real Phones?

This is where the debate gets more nuanced. From a benchmark-driven, spec-sheet perspective, efficiency cores look increasingly expendable in high-end phones. Modern big and medium cores on 2nm or even 3nm nodes can idle at tiny voltages, wake up quickly, and go back to sleep just as fast. For light tasks – messaging, scrolling social feeds, notifications – it’s entirely plausible that a downclocked “big” core can be as frugal as yesterday’s little core while giving you snappier responsiveness.

On the other hand, everyday users don’t sit there running Geekbench on loop until their phone throttles. They care about how smooth the UI feels, whether the battery survives a long day, and if the phone stays cool while binge-watching or gaming. From that angle, Samsung’s insistence on keeping efficiency cores doesn’t look completely irrational. If those little cores let the phone sip power at idle, keep background tasks in check, and leave more thermal budget for the GPU when a game kicks in, many people will never complain that the CPU “only” ranks second in synthetic charts.

There’s also a fair argument that modern mobile CPUs, almost across the board, are more than fast enough for typical phone workloads. A phone isn’t a full productivity machine for most people – anything remotely serious is still easier on a laptop or a proper hybrid device. That means the user experience ceiling is often dictated not by the last five percent of CPU performance but by thermal design, GPU strength, storage speed, display quality, and software optimization.

Where MediaTek and Samsung really differ is how they balance those realities. MediaTek has embraced the idea that flagship buyers want uncompromising headline performance, even if that means flirting with higher power draw and complex thermal management. Samsung, burned by past thermal scandals, has taken the opposite route: risk-averse, sometimes too cautious, prioritizing theoretical efficiency and safety even when the manufacturing node – especially with 2nm GAA – may finally be good enough to support a bolder design.

MediaTek vs Samsung: Two Philosophies, Both With Trade-offs

MediaTek’s core configs can look strange, even excessive, to outsiders. Critics are right to point out that packing in lots of big cores at high clocks can encourage manufacturers to chase impressive benchmarks that don’t always reflect real-world behavior. If the chip quickly ramps to maximum power, posts a great score, and then throttles in your favorite game, the spec sheet won’t comfort you. For users who primarily care about sustained gaming performance and cool operation, an “all big” CPU that lives on the edge may feel more like a party trick than a practical advantage.

Samsung, meanwhile, has played the role of the nervous perfectionist. Its engineers keep layering efficiency cores into designs as if they’re an insurance policy against thermal disaster, even when the underlying node is finally capable of doing more. The Exynos 2600 engineering samples already suggest that the silicon itself is far from weak. The lingering question is whether the architecture and core mix are fully aligned with what this node could actually deliver, or whether old habits are still shaping new chips.

In this light, efficiency cores aren’t so much “futile” as they are a symbol of an older design mindset. They made perfect sense when process nodes were rougher and big cores were genuinely wasteful at low loads. But as nodes mature, the opportunity cost of dedicating area and design complexity to tiny cores grows. For Exynos in particular, hanging on to them feels less like a necessity and more like a safety blanket from the era when any aggressive move risked another thermal scandal.

What Samsung Needs From Exynos 2700 and Beyond

If Samsung really wants Exynos to go toe-to-toe with Qualcomm and MediaTek at the top end, the company has to start designing like its process node is an asset, not a liability. That likely means simplifying the CPU layout, putting more faith in powerful mid cores that can scale down efficiently, and doubling down on GPU and NPU performance, where real-world workloads are clearly headed.

The leaked Exynos 2600 numbers prove that Samsung is finally within striking distance. Imagine that same chip with a leaner core mix, all silicon focused on performance-per-watt rather than babysitting duties, and a scheduler tuned for the reality that phones spend most of their time at light to moderate load. It wouldn’t just match the Dimensity 9500 – it might redefine what an Exynos flagship can be.

Until then, MediaTek’s Dimensity 9500 stands as a case study in how daring architectural bets can pay off, and how quickly industry “rules” can change. Efficiency as a goal will always matter in mobile, but efficiency cores as a rigid design requirement are clearly under trial. Right now, the verdict for Samsung is simple: the 2nm era is the perfect time to stop designing like it’s still 2018 and finally let Exynos step onto the same stage as Dimensity and Snapdragon without a safety net.