How A Raspberry Pi 4 Performs Against Intel's Latest Celeron, Pentium CPUs

[TheOne]

What I would like yo see is an Odroid N2+ comparison, that should be more interesting since it is a more powerful sbc than the RPI4

[bnolsen]

why run 32-bit on the Pi 4 instead of 64-bit? 64-bit is faster for a lot of workloads due to having more registers.

oof i've seen so,e yotube reviews on the pi and the 64 bit clearly outperforms 32 bit.

[vladpetric]

And how is that so bad when you consider the advantages the RPi4 has?

You're right, ARM chips aren't known for overclocking well. But you're not supposed to do push them to the performance of desktop x86 chips. Using the economy car example again, there's only so much a turbo or supercharger is going to do to make that car have enough power without blowing up.
Nobody in their right mind would buy an ARM chip in the hopes of having competitive processing power with a laptop or desktop x86 CPU. You buy ARM because it sips power with reasonable performance. I don't get why you're so focused on performance when that's not the point of going for ARM.

There is no such thing as a one-size-fits-all approach, not even in processors. So no actually, my analogy works fine. As I already told you - Intel tried to compete with ARM but x86 downscales terribly once you get below 20W. Not even AMD is truly competitive in this segment yet and their design so far is more efficient than Intel's. Your example of a "superfast processor" is either not necessary, viable, or practical in ARM's target markets (like phones, routers, or web servers).
The reason Apple's architecture works well is because of their own added instructions and a LOT of OS-level optimizations. Since they control the platform, they don't have to do generic builds of anything; they can fine-tune things with mediocre hardware. I'm sure Apple will be adding on more cores to their desktop ARM CPUs instead of more MHz.

Michael has done tests in the past showing performance-per-watt (maybe not with ARM+x86 in the same article, but you can get the data from both) using an external watt meter. But, many ARM SBC users get 15W power bricks and they work perfectly fine. If you don't overclock or use something power-hungry like wifi or a USB HDD, you can easily get by with a 10W adapter. I personally have powered a system with a 5W adapter, but all it had plugged into it was a keyboard, mouse, and ethernet.

I agree that there isn't really a one size fits all. For instance, there are really low power/low cost microcontrollers (e.g. PICs). Still, it's a disappointment that ARM implementations from ARM itself are doing poorly (that's how I view things).

The main reason Apple ARMs work so well is because they hired Jim Keller and a few other people to build a high quality microarchitecture, which gives really good IPC, and good performance per Watt as well. Look, IPC matters a lot, you really can't ignore it.

Let me repeat something I said in my first post - RPi4 (Cortex A72) doesn't even have a proper load-store queue, to issue loads speculatively wrt prior stores. What are your thoughts on that?

I'm not making a statement about Intel here (you don't need to repeat yourself). I'm not saying at all that Intel's doing ok - I'm saying that RPi 4 is performing poorly. And Intel does have actual low-power chips as well (Y series) - probably OEM only (harder to benchmark), and expensive as hell (yes, cost matters too ... no doubt about it).

Well, I'd really be interested in Michael doing some perf per watt numbers. I'd also be interested in instruction counts and IPC data for the benchmarks. Just sayin ...

[caligula]

I would have expected a bigger divide.

RPi has made great strides over the years. Love seeing the chasm closing. I'd love to see a graph over time of generally how the performance gap has closed. Certainly we'd see that ARM is improving at a much faster rate than x86.

The comparison isn't totally fair since RPi4 is like 2 to 4 times as expensive as the first RPis. I'd imagine a $2000 CPU also performed faster than a $500 CPU.

[Jabberwocky]

why run 32-bit on the Pi 4 instead of 64-bit? 64-bit is faster for a lot of workloads due to having more registers.

+1 I love the idea of the raspberry pi, but I'm not a fan of the raspberry pi foundation.

They made no blog posts about CPU vulnerabilities and only support 32bit OS with no way to switch off HDMI on custom c runtimes.

Edit: I would like to see Pi 3 B+ in the comparison too, as well as performance/watt.

[elatllat]

What I would like yo see is an Odroid N2+ comparison, that should be more interesting since it is a more powerful sbc than the RPI4

[CommunityMember]

i've seen so,e yotube reviews on the pi and the 64 bit clearly outperforms 32 bit.

As with all else, your mileage will vary (the same is true for x86, usually the compiler can do better in 64-bit mode, but there are exceptions where running in 32-bit mode is faster). Benchmarks prove which system is faster for that benchmark. Since I don't run benchmarks for production (unlike Jack Dongara, or, in this case, Michael), while benchmarks are indicative, your (and my) mileage will vary.

[schmidtbag]

I agree that there isn't really a one size fits all. For instance, there are really low power/low cost microcontrollers (e.g. PICs). Still, it's a disappointment that ARM implementations from ARM itself are doing poorly (that's how I view things).

They're doing poorly because you're judging it for something it wasn't meant to do. As the saying goes, "judge a fish by its ability to climb a tree and it will think it's stupid". ARM isn't built to compete with desktop performance.

The main reason Apple ARMs work so well is because they hired Jim Keller and a few other people to build a high quality microarchitecture, which gives really good IPC, and good performance per Watt as well. Look, IPC matters a lot, you really can't ignore it.

Yes, I basically said that myself but in fewer words.
IPC can matter a lot. It isn't the only thing that matters.

Let me repeat something I said in my first post - RPi4 (Cortex A72) doesn't even have a proper load-store queue, to issue loads speculatively wrt prior stores. What are your thoughts on that?

I don't know enough about that to make a worthwhile comment on it, which is why I didn't comment on it in the first place. What I do know is it clearly isn't a necessity to make ARM usable on a day to day basis, of course, assuming you're ok with the level of performance (which plenty of people are). I feel like if it was such an obvious thing to add, they would have done so. After all, the NEON instructions for example aren't exactly a simple addition.

I'm not making a statement about Intel here (you don't need to repeat yourself). I'm not saying at all that Intel's doing ok - I'm saying that RPi 4 is performing poorly. And Intel does have actual low-power chips as well (Y series) - probably OEM only (harder to benchmark), and expensive as hell (yes, cost matters too ... no doubt about it).

Poorly compared to what? You have to make comparisons, and the context of the article included Intel. ARM is a hell of a lot better compared to most, if not all other RISC architectures (POWER is faster but it is a lot more power hungry too). Apple's CPU might be better, but it's not going to be cheap; this Broadcom chip offers some fantastic performance[-per-watt] for the price. Any CPU can be made better if you just cram more instructions in it, but then it becomes expensive and inefficient for more basic tasks. Like I said multiple times already: you're expecting this CPU to be something it's not. It does what it was built to do very well.

Well, I'd really be interested in Michael doing some perf per watt numbers. I'd also be interested in instruction counts and IPC data for the benchmarks. Just sayin ...

Me too. Though, kinda the point of these CPUs is they don't have a lot of instructions. My server uses A53 cores (not Broadcom) and this is all it shows for features in cpuinfo:
half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt lpae evtstrm aes pmull sha1 sha2 crc32
Sure isn't much to look at, eh? But it's fast enough for what I need it to do.

[starshipeleven]

ARM isn't built to be performant. It's built to be efficient.

Is it really?
ARM is an architecture that is supposed to scale up into the high-performance too.

The Raspi and embedded devices in general are designed to be efficient, but there are high-end ARM CPUs that really need a real heatsink.

[starshipeleven]

ARM isn't built to compete with desktop performance.

This is your own idea.
There is higher end stuff from Marvell and NXP and whatever that is using high-performance CPU designs licensed from ARM, there are Apple ARM designs where they are designing their own cores from scratch and are actually pretty decent for desktop/laptop. There are custom ARM designs from Amazon, again nothing like ARM's CPU designs.
NVIDIA's jetson and whatnot boards too.

That guy is talking about SPECIFIC CPU core designs from ARM (the ones that are licensed to third parties) being inferior, which is at least somewhat believable at face value.

You are just assuming a whole architecture/ISA is the same just because it has the same interface for software, which is complete bullshit.