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?
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.
With better CPUs encroaching on the Athlon II X2 250's price point, we shed a few dollars and reinstated the 245 as our choice for a gaming CPU on a rock-bottom budget.
This chip allows the flexibility to go one of two different ways: either drop it in as an upgrade for your Socket AM2+-based platform or build a brand new, low-cost Socket AM3 machine based on it. With a high 2.9 GHz clock speed, the Athlon II X2 245 offers excellent gaming performance at the price. Moreover, its 65W thermal design power is great for electricity- and heat-conscious enthusiasts.
Best Gaming CPU for ~$75:
Athlon II X3 435
Athlon II X3 435
Codename:
Rana
Process:
45nm
CPU Cores:
3
Clock Speed:
2.9 GHz
Socket:
AM2+/AM3
L1 Cache:
3 x 64KB
L2 Cache:
3 x 512KB
HyperTransport:
4,000 MHz
Thermal Envelope:
95W
The Athlon II X3 435 boasts three execution cores. And, compared to a dual-core processor, that extra core will make a notable difference in multi-tasking performance, as well as game play. This model also has good overclocking headroom if you want to push it a little further. On top of everything else, it recently dropped in price now that the new Athlon II X3 440 model has arrived.
Best gaming CPU for ~$90:
Athlon II X3 440
Athlon II X3 440
Codename:
Rana
Process:
45nm
CPU Cores:
3
Clock Speed:
3.0 GHz
Socket:
AM2+/AM3
L1 Cache:
3 x 64KB
L2 Cache:
3 x 512KB
HyperTransport:
4,000 MHz
Thermal Envelope:
95W
From a stock performance standpoint, the Athlon II X3 440 only offers a 100 MHz speed bump over the Athlon II X3 435. However, the higher multiplier might help if your ultimate goal is overclocking.
When you consider the big picture, this CPU really offers an attractive combination of multiple CPU cores, high clock speed, low price, and overclockability. It is such a great gaming CPU, in fact, that it almost renders most of the CPUs in the $100 to $130 range redundant. As a result, most of our recommendations in this range are aimed specifically at overclockers and users upgrading an older platform.
Best Gaming CPU: $90-$110
Best gaming CPU for $100
Athlon II X4 620
Athlon II X4 620
Codename:
Propus
Process:
45nm
CPU Cores:
4
Clock Speed:
2.6 GHz
Socket:
AM3
L1 Cache:
4 x 128KB
L2 Cache:
4 x 512KB
HyperTransport:
4,000 MHz
Thermal Envelope:
95W
Frankly, the high clock rate of the Athlon II X3 440 allows it to perform better than an Athlon II X4 620 at stock frequencies in a great majority of games.
However, there are a few titles out there that will take advantage of a fourth CPU core, making the Athlon II X4 a potentially-attractive choice to buyers who want all four CPU cores and are willing to overclock this processor. Moreover, as a general-purpose CPU (during the hours you don't spend gaming, of course), the quad-core solution is going to be superior. Now found as low as $96, true quad-core CPUs are well within the grasp of the budget gamer.
Phenom II X2 555 Black Edition
Phenom II X2 555 Black Edition
Codename:
Callisto
Process:
45nm
CPU Cores:
2
Clock Speed:
3.1 GHz
Socket:
AM3
L1 Cache:
2 x 128KB
L2 Cache:
2 x 512KB
L3 Cache:
6MB
HyperTransport:
4,000 MHz
Thermal Envelope:
80W
Although the dual-core Phenom II X2 555 Black Edition might be a bit slower than the less-expensive Athlon II X3 435 when it comes to gaming, it offers something that the Athlon II X3 doesn't have: an unlocked clock multiplier. Like all of AMD's Black Edition processors, the Phenom II X2 555 can be easily overclocked by simply upping its multiplier in the motherboard BIOS of your choice, earning this CPU a place on our recommended list for overclocking fans. Found online at $100, this CPU offers high-end overclocking features for a budget price.
Increased availability over the past few weeks cements our honorable mention status for this chip, which, again, is best suited to the enthusiasts willing to finesse its clock rate as high as possible.
Best Gaming CPU: $110-$130
Best gaming CPU for $110-$130
Athlon II X4 635
Athlon II X4 635
Codename:
Propus
Process:
45nm
CPU Cores:
4
Clock Speed:
2.9 GHz
Socket:
AM3
L1 Cache:
4 x 128KB
L2 Cache:
4 x 512KB
HyperTransport:
4,000 MHz
Thermal Envelope:
95W
Offering a 100 MHz speed boost over the Athlon II X4 630, the new Athlon II X4 635 cannot be denied as a good option for overclockers who want four processing core.
This model isn't unlocked (it's not one of AMD's Black Edition chips), but it does sport a higher multiplier than the Athlon II X4 630, making it a solid quad-core processor with (ideally) a bit of scalability on the cheap. With a $120 asking price, there is a lot of value here.
Core i3-530
Core i3-530
Codename:
Clarkdale
Process:
32nm
CPU Cores/Threads:
2/4
Clock Speed:
2.93 GHz
Socket:
LGA 1156
L1 Cache:
4 x 32KB
L2 Cache:
2 x 256KB
L3 Cache:
4MB
Thermal Envelope:
73W
The performance picture has gotten a little clearer since last month, and while the Core i3-530 looks like a promising CPU, it probably doesn't justify a full recommendation at the $125 price point. We're going to wait until we've done our own extensive benchmarking before we make the call, but until then, we can heartily give this processor an honorable mention as a viable alternative for folks in the market for an LGA 1156-based platform. At $125, this CPU is a great starting point.
Stock performance is usually quite good from what we've seen, although you can't expect Hyper-Threading to yield the same performance gains as an additional two physical cores.
Core 2 Duo E7500
Core 2 Duo E7500
Codename:
Wolfdale-3M
Process:
45nm
CPU Cores:
2
Clock Speed:
2.93 GHz
Socket:
LGA 775
L2 Cache:
3MB
Front Side Bus:
1,066 MHz
Thermal Envelope:
65W
At 2.93 GHz, the Core 2 Duo E7500 remains a good match-up against the Phenom II X3 720 Black Edition. Even without an unlocked multiplier, the E7500 is an excellent overclocker and won't disappoint. And the $116 price point is easy to swallow for upgraders.
It has a high clock rate, but its dual-core design won't be as nimble as AMD's triple-core offerings when it comes to multi-threaded apps. Most folks considering this CPU are probably trying to squeeze longevity from an older LGA 775 platform. If you're looking to upgrade your motherboard as well, it'd be best to consider a Phenom II or Core i3 instead.
At 2.93 GHz, the Core 2 Duo E7500 remains a good match-up against the Phenom II X3 720 Black Edition. Even without an unlocked multiplier, the E7500 is an excellent overclocker and won't disappoint. And the $116 price point is easy to swallow for upgraders.
It has a high clock rate, but its dual-core design won't be as nimble as AMD's triple-core offerings when it comes to multi-threaded apps. Most folks considering this CPU are probably trying to squeeze longevity from an older LGA 775 platform. If you're looking to upgrade your motherboard as well, it'd be best to consider a Phenom II or Core i3 instead.
Phenom II X3 720 Black Edition
We try and stick to retail processors when it comes to CPU recommendations because the costs of a cooler introduces a sizable variable. But in the case of the Phenom II X3 720, flagging retail availability forces us to make an exception.
The OEM version of this CPU is now $105. Add a $15 aftermarket cooler, and you have a triple-core unlocked CPU on your hands for $120.
We're a bit torn here. On the one hand, we know that overclocking is the surest way to negate your warranty coverage. However, the Phenom II X3 720 Black Edition not only has that unlocked multiplier, but we've also had some luck unlocking the fourth core on a handful of samples. The chance may or may not be worth the extra money you drop in this chip. Bear in mind, though, that it's an "expensive" model for AMD to sell, and its starting to disappear fast. We're already having trouble finding the retail version available online.
Best Gaming CPU: $140-$195
Best gaming CPU for $140
Core i3-540
Core i3-540
Codename:
Clarkdale
Process:
32nm
CPU Cores/Threads:
2/4
Clock Speed:
3.06 GHz
Socket:
LGA 1156
L1 Cache:
4 x 32KB
L2 Cache:
2 x 256KB
L3 Cache:
4MB
Thermal Envelope:
73W
Another one of Intel's new Core i3 processors, the gaming data we have seen for this i3-540 looks promising. While it isn't going to perform all that much better than the -530, its higher multiplier will be a boon for overclockers, and the price might be justified for some.
Bear in mind that, although Intel launched this processor alongside the H55 and H57 chipsets, gamers are likely going to want to stick with P55 when they shop for an LGA 1156-equipped motherboard, even if it means ignoring the integrated graphics core built onto the Core i3-540. When used with Clarkdale-based processors, Intel's H55 and H57 chipsets aren't able to divide on-package PCI Express connectivity between CrossFire and SLI graphics configurations.
Best gaming CPU for $160:
Phenom II X4 955 Black Edition
Phenom II X4 955 Black Edition
Codename:
Deneb
Process:
45nm
CPU Cores:
4
Clock Speed:
3.2 GHz
Socket:
AM3
L1 Cache:
4 x 128KB
L2 Cache:
4 x 512KB
L3 Cache:
6MB
HyperTransport:
4,000 MHz
Thermal Envelope:
125W
A former flagship of AMD's Phenom II family, the Phenom II X4 955 BE has been relegated to second-place status by the newer Phenom II X4 965 BE model. Now at $160, it offers a very compelling price/performance ratio for a true quad-core unlocked processor with gobs of cache.
Best gaming CPU for $180
Phenom II X4 965 Black Edition (New C3 stepping)
Phenom II X4 965 Black Edition (C3 Stepping)
Codename:
Deneb
Process:
45nm
CPU Cores:
4
Clock Speed:
3.4 GHz
Socket:
AM3
L1 Cache:
4 x 128KB
L2 Cache:
4 x 512KB
L3 Cache:
6MB
HyperTransport:
4,000 MHz
Thermal Envelope:
125W
While the Phenom II X4 955 and 965 both share an unlocked multiplier, the new revision 965 model's C3 stepping has been shown to be quite overclock-friendly compared to previous models. If you're looking for an AMD processor with the maximum overclocking headroom, just make sure you're buying the new 125 watt C3 stepping of the processor, not the older 140 watt version.
Best gaming CPU for $190
Core 2 Quad Q9400
Core 2 Quad Q9400
Codename:
Yorkfield
Process:
45nm
CPU Cores:
4
Clock Speed:
2.66 GHz
Socket:
LGA 775
L2 Cache:
2 x 3MB
Front Side Bus:
1,333 MHz
Thermal Envelope:
95W
The Core 2 Quad line isn't as strong as Intel's lone Lynnfield-based Core i5 model, but the older processors certainly aren't slouches either. On a clock-for-clock basis, the Core 2 Quad tends to perform a little bit better than AMD's Phenom II X4.
The Core 2 Quad Q9400 is a strong competitor for the Phenom II X4 955 and will overclock well, despite its locked CPU multiplier. Even in the face of a somewhat low stock clock, 6MB of shared L2 cache and a speedy 1,333 MHz front side bus help the chip compete aggressively for less than $200. With the Phenom II X4 965 and Core i5-750 priced so close, this one should only really be a consideration for the gamer upgrading an LGA 775-based machine.
This will happen. In fact, it's guaranteed to happen because availability and prices change quickly. So how do you know if that CPU you've got your eye on is a good buy in its price range?
Here is a resource to help you judge if a CPU is a good buy or not: the gaming CPU hierarchy chart, which groups CPUs with similar overall gaming performance levels into tiers. The top tier contains the highest-performing gaming CPUs available and gaming performance decreases as you go down the tiers from there.
However, a word of caution: this hierarchy is based on the average performance each CPU achieved in our charts test suite using only four game titles: Crysis, Unreal Tournament 3, World in Conflict, and Supreme Commander. While we feel this represents an acceptable cross-section of typical gaming scenarios, a specific game title will likely perform differently. Some games, for example, will be severely graphics subsystem-limited, while others may react positively to more CPU cores, larger amounts of CPU cache, or even a specific architecture. We also did not have access to every CPU on the market, so some of the CPU performance estimates are based on the numbers similar architectures deliver. Indeed, this hierarchy chart is useful as a general guideline, but certainly not as a gospel one-size-fits-all perfect CPU comparison resource.
You can use this hierarchy to compare the pricing between two processors, to see which one is a better deal, and also to determine if an upgrade is worthwhile. I don't recommend upgrading your CPU unless the potential replacement is at least three tiers higher. Otherwise, the upgrade is somewhat parallel and you may not notice a worthwhile difference in game performance.
