Intel Pentium 4 Vs. Atom: A Battle Of The Generations

Most people know that Intel’s Atom is a slow, low-cost processor. But does it even offer enough performance to take it beyond desktop processors nearly a decade old? Today we're comparing a modern Atom CPU to two Northwood-class Pentium 4-based PCs.

We were sorting out some old hardware in one of our test labs and wondered what to do with our old Socket 478 Pentium 4 gear. Disposing of it doesn’t feel quite right, and we know that many Pentium 4 systems remain in service. Clock speeds between 2 GHz and 3.4 GHz still provide sufficient performance for a home server or backup PC, so why not put up two different Pentium 4 systems against single-core and dual-core Atom solutions to see how today’s low-cost computing solutions hold up?

Convenience Computing

We done several articles dealing with Atom and comparing its performance and efficiency with other solutions. First and foremost, it’s important to note that Atom is not in the same market segment as desktop-oriented Core 2, Core ix, Phenom, or Athlon processors. Atoms enable the lowest-cost netbooks and nettop computers. They aren’t meant to be particularly efficient, and they won’t satisfy a power user. Any entry-level Core i3 desktop will provide many times better power efficiency, in fact.

Atom makes sense where local computing performance doesn’t matter very much: browsing the Internet, communicating via email or social networks, and processing documents and spreadsheets. For these, Atom is more than enough.

Buy Atom or Recycle P4?

Does it make more sense to purchase a cheap Atom-based computer or to recycle and/or continue to use an existing Pentium 4 machine? Both run at decent clock speeds and come with 512 KB of L2 cache. Both can be considered above average if you have modest performance expectations. And both have a comparable transistor count: 55 million for the Pentium 4 (based on the Northwood design) and 47 millions for the Atom 230.

More importantly, you might be able to get an older P4 system for very little money from a friend or business upgrading to newer hardware. We compare the Atom 230 and D510 to a Pentium 4 (Northwood) 2.2 and 3.2 GHz.

Oldie But Goldie: Intel Pentium 4 (Northwood)

The Northwood-based Pentium 4 was the first processor to employ Intel’s Socket 478 interface and dual-channel memory. It was the second Pentium 4 generation, and it utilized a 130 nm CMOS manufacturing process with 512 KB of L2 cache and clock speeds between 1.6 and 3.4 GHz. Early versions were based on a 400 MHz front-side bus speed (100 MHz) while faster models ran at 800 MT/s (200 MHz) and used dual-channel DDR-400 memory. 

The step to an 800 MT/s FSB and the 865/875 Express chipsets brought substantial change. Intel introduced its LGA 775 interface and the 90 nm Prescott core in 2003, but since these chips increased power consumption without introducing an equivalent performance increase, we decided to stay with the older platform for this review.

First, we tested a Pentium 4 at 2.2 GHz. This is a 400 MT/s FSB design that didn’t support Hyper-Threading. In order to get the comparison numbers with HT, we also added a Pentium 4 C at 3.2 GHz. Hyper-Threading is valuable bcause the operating system perceives two processing cores for every physical core. The technique is better at saturating the Northwood’s long, 20-stage pipeline. The 3.2 GHz model runs on an 800 MT/s FSB with a maximum TDP of 89 W, while the 2.2 GHz model stays below 57.1 W.

Obviously, the 3.2 GHz version is much faster, but it also drains significantly more power at idle and under heavy loads. Keep in mind that processors in 2002 did not have power saving mechanisms like SpeedStep. As a result, both Pentium 4 systems require at least twice the idle power than our Atom solutions and up to five times the peak power. Will the Pentium 4 system be capable of delivering performance in about the same range?

DFI’s LANParty Pro 875B with an ATI Radeon 800 Pro served for this project.

Better Than Its Reputation? Intel's Atom

Atom 230

The Atom 230, also known as Diamondville, was Intel’s first Atom generation. It comes with clock speeds of up to 1.6 GHz and a 133 MHz front-side bus. It also supports Hyper-Threading, like the Pentium 4, and has the same 512 KB of L2 cache. But this is all they really have in common.

While the Pentium 4s we used are 130 nm products, the Atom uses Intel’s 45 nm process. The limited clock speed paired with the modern manufacturing process helps the single-core chip to stay within a thermal envelope of only 4 W. Unfortunately, the whole Atom platform doesn’t necessarily save power, since Atom 230 typically pairs with the terribly inefficient 945GC. Still, if you only look at the CPU, Atom does really well.

A direct comparison between the Pentium 4 and the Atom 230 at 1.6 GHz reveals little in common. The Atom 230 significantly trails the Pentium 4 in some tests, while it stays fairly even with the Pentium 4 2.2 GHz in others. The MP3 encoder Lame runs much faster on the Pentium 4 systems. So do Adobe Acrobat, iTunes, and WinZip. However, the 1.6 GHz Atom 230 actually does better than a Pentium 4 2.2 GHz in 7-Zip and Adobe Photoshop CS4, and it’s not too far behind in HandBrake and MainConcept, although the overall results are awfully slow on both platforms. Still, the Atom supports more advanced SSE instructions, which may explain a part of the results.

Atom D510

The second-gen Atom D510 is a dual-core part based on the Pineville core. It’s based on the same execution core as the first-generation Atom, which is why it doesn’t really deliver more performance per clock than Diamondville. The new CPU is rated at a 13 W TDP, which looks like a lot more than the initial Atom’s 4 W. However, Atom D510 includes a more advanced graphics engine and memory controller, making the northbridge obsolete. This clearly helps the latest Atom reduce overall platform power consumption by going from three chips to two.

The CPU runs at a similar clock speed as before, now 1.66 GHz with a 133 MHz quad-pumped front-side bus. The two cores still support 64-bit operation and Hyper-Threading, which means that the operating system can access four logical processing cores.

Test Systems And 3DMark Vantage

System Hardware
Hardware	Details
Performance Benchmarks
Motherboard I	Intel D510MO (Rev. 1.0), Chipset: Intel NM10, BIOS: 0175 (03/8/2010)
Motherboard II	Elitegroup 945GCT-D (Rev. 1.0), Chipset: Intel 945GC, BIOS: 08/07/08
Motherboard III (Socket 478)	DFI LANParty PRO875B (Rev. B), Chipset: Intel 875P, BIOS: 1.2 (05/21/2005)
CPU Intel I	Intel Atom D510 (45 nm, 1.66 GHz, 1 MB L2 Cache, TDP 13 W)
CPU Intel II	Intel Atom 230 (45 nm, 1.6 GHz, 512 KB L2 Cache, TDP 4 W)
CPU Intel III	Intel Pentium 4 2.2 GHz (130 nm, 2.2 GHz, 512 KB L2)
CPU Intel IV	Intel Pentium 4 3.2 GHz (130 nm, 2.2 GHz, 512 KB L2)
RAM DDR (dual)	2 x 1 GB DDR2-400 (Corsair CMX1024-3200C2) 2 x 1 GB DDR2-400 (Corsair CMX1024-3500LLPRO)
RAM DDR2 (dual)	2 x 2 GB DDR2-800 (Apogee AU2G732-12GH001)
RAM DDR3 (dual)	2 x 2 GB DDR3-1333 (OCZ3G2000LV4GK 8-8-8-24)
Graphics Card (AGP)	Radeon AX800 Pro, 256MB
Hard Drive	Seagate Barracuda 7200.11, 500 GB (ST3500320AS), 7200 RPM, SATA 3Gb/s, 32 MB Cache
Power Supply	Enermax Pro 82+, EPR425AWT
System Software & Drivers
Operating System	Windows 7 Ultimate x64 Updated on 2010-05-10
Drivers and Settings
Intel Chipset Drivers	Chipset Installation Utility Ver. 9.1.1.1025
Intel Storage Drivers	Matrix Storage Drivers Ver. 8.​9.​0.​1023
Intel Graphics 945G	Intel Graphics Media Accelerator 15.​12.​75.​4.​1930
Intel Graphics NM10	Intel Graphics Media Accelerator 15.​12.​75.​50.​5.​2117

3DMark06

3DMark is not a particularly notable test in this article, as we armed the Pentium 4 system with a Radeon X800 Pro graphics card. The Atom systems output via their integrated GMA 950 and GMA 3150 graphics processor, which deliver much lower results compared to the discrete ATI card, despite its age.

In the CPU test, the dual-core Atom D510 does well, delivering the best performance in this benchmark section.

Once graphics performance is involved, both Atom solutions don’t stand a chance anymore.

Benchmark Results: Synthetics

SiSoftware Sandra 2010

The Atom 230 predictably falls behind in most tests from its lack of horsepower.

We found it more interesting to watch the dual-core Atom D510 dominate our Sandra test runs with the exception of the memory bandwidth test. Two modern 1.66 GHz cores are sufficient to beat the ancient, massive Pentium 4 at 3.2 GHz in some of the tests.

Benchmark Results: Applications

3ds Max is heavily optimized to utilize multiple processing cores, and even though the single-core Atom loses, the dual-core comes out as winner.

7-Zip also runs best on the Atom D510 dual-core. Interestingly, the Atom 230 single-core does better than the Pentium 4 2.2 GHz in this benchmark, most likely because of SSE optimizations.

Benchmark Results: Audio/Video

iTunes is not optimized for multi-core processors. This workload obviously favors higher clock rates.

The same applies for the Lame MP3 encoder.

Video transcoding prefers the dual-core CPU.

HandBrake video transcoding is quickest on the Atom D510 dual-core CPU.

Benchmark Results: Power Consumption

Obviously, idle power is lowest on the newest system as a result of its more advanced silicon manufacturing process and degree of integration.

Despite its two cores, the new Atom D510 offers lower idle power than the single-core Atom 230, thanks to platform-based improvements.

Both Pentium 4 systems require idle power similar to what a current machine based on an Athlon II, Phenom II, or Core i3/i5/i7 would require when utilizing a discrete graphics solution.

Peak power on the Atom machines doesn’t change too much in comparison with the idle power results. The Pentium 4 side, however, requires considerably more power, which tells us that power efficiency should be rather poor on these old setups, since performance fails to scale upward with power consumption.

Benchmark Results: Efficiency

The Atom systems are pretty constant when it comes to power consumption. A 30 W to 35 W average draw during our efficiency run is a good result. The P4 machines require 3x to 5x more.

Total power used is lowest on the dual-core Atom D510 because it completes our workload quicker than the single-core Atom 230 while consuming even less power. Both Pentium 4 systems are comparable. The faster 3.2 GHz unit requires more power, but it’s faster, and hence finishes quicker. Nevertheless, we measured that the 2.2 GHz Pentium 4 actually requires less power to complete our efficiency workload.

The dual-core Atom D510 provides top performance. The single-core Atom 230 is slowest.

If you look at performance related to watt-hours used, the Atom solutions deliver many times better power efficiency. Looking at this diagram alone proves that it doesn’t make sense to keep a Pentium 4 machine if you can afford a low-cost Atom nettop PC.

The efficiency diagram visualizes power consumption throughout the workload and the total runtime of each system.

Conclusion

It is possible to take an old Pentium 4 system and revive it for basic applications. Whether as a home/multimedia server or as a backup client PC, Intel’s old platform works well, so long as you don’t have tall performance expectations. However, we wanted to know how it would compare to an Atom nettop platform, so we pitted Pentium 4 systems at 2.2 GHz and 3.2 GHz against an Atom 230 single-core and the new Atom D510 dual-core.

Performance? Don’t Expect Too Much

Performance-wise, there are benchmarks in which the old Pentium 4 still does well. This applies to workloads that haven’t been multi-threaded or coded to take advantage of newer instruction set enhancements, such as SSE3. All others, though, run much faster on the dual-core Atom D510, mostly thanks to its second processing core. The performance difference is glaring.

Note that all of the test systems deliver rather limited performance if you compare them to a modern PC based on an AMD Athlon II, Phenom II, or Intel’s Core i3/i5/i7. We’re clearly talking about entry-level performance in this article.

Power and Efficiency

Performance alone might not be much of an issue, as the applications we’ve mentioned don’t require much computing power. However, the power consumption and power efficiency are even more important. Both Atom systems are role models of quiet operation and low power consumption. In contrast, the Pentium 4 systems require three to five times more power at idle and under load. Whether or not you care about your power bill, this definitely has an impact on cooling and noise.

Eight Years Are Enough!

In the end, there’s a simple conclusion for everyone who wants a low cost system: keep your old Pentium 4 system if you have to, but bear in mind that all relevant metrics (performance, noise, power, and efficiency) are pathetic by modern standards.

If you can afford to spend a few hundred dollars on a nettop, we’d definitely recommend this. We usually rant about Atom due to its shortcomings compared to desktop platforms, but it simply trounces the old P4s. Keeping a PC in service for seven or eight years is more than enough. Just make sure you go for a dual-core Atom when you decide to buy.

source:Tom's Hardware > All Reviews > Components > CPU > Intel Pentium 4 Vs. Atom: A Battle Of The GenerationsIntel Pentium 4 Vs. Atom: A Battle Of The Generations

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