How to Choose a Processor / CPU?
By Dr. Michael, Lee Penrod, Benjamin Wieberg, and David Boss
Updated December 16, 2014
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In the current market you have fourteen main categories of microprocessors to choose for your desktop computers: Ivy Bridge Core series, Sandy Bridge Core series, Core 2 Duo, Core 2 Quad, Pentium Dual Core, Celeron, Xeon, Phenom, Phenom II, AthlonII X2, Athlon X2, Athlon 64, Sempron, and Opteron.
Intel’s Tick-Tock Strategy:
Intel develops chip technologies in two phases. The “tick” phase is where they shrink the die down a smaller size. The “tock” phase is where they increase efficiency in their shrunken design.
Intel Core i3, i5, i7: Socket 1150
Haswell is one of the newer Core lines that follows Intel’s Ivy Bridge architecture. This was considered a “tock” in their release strategy as it is based on new microarchitecture, although it shares the same shrunk die size with Ivy Bridge at 22nm. There have been two iterations of Haswell, the newest iteration (Haswell refresh) having higher clock speed with relatively the same power input required. Higher efficiency is a trend we see many electronic companies shifting towards. Haswell utilizes socket 1150, which is incompatible with previous generations of Intel processors. The two iterations of Haswell are used in combination with Intel 8 and 9 series chipsets. For power users this means Z87 and Z97 motherboards will be optimal for performance. DDR3 is still the memory standard being utilized for now.
Intel Core i3, i5, i7: Socket 1155
Sandy Bridge is the name for the microarchitecture developed by Intel to replace Nehalem and socket 1366, congruent with their “tock” strategy. These products were first released in 2011 and use a 32 nanometer manufacturing process. These Core products implement a new socket called LGA 1155, which is incompatible with earlier processors. These processors support Hyper-Threading, PCI Express 2.0, DDR3, DirectX 10.1 capabilities, and have integrated graphics (Intel HD Graphics 2000 or 3000).
Ivy Bridge is the successor to Sandy Bridge, and is the current generation processor. This is congruent with Intel’s “tick” strategy of processor release. Socket 1155 is still used, although the BIOS sometimes requires an update with motherboards first designed for Sandy Bridge. With this iteration, Intel has shrunk the die size from 32nm to 22nm. A shrink in die indicates that the processor has become more efficient, consequently increasing its speed and a decreasing its power draw. These processors support PCI Express 3.0, DDR3L, are DirectX 11 capable, and have improved integrated graphics (Intel HD Graphics 3000 or 4000). However, it should be noted that you’ll still need a dedicated video card to play graphic demanding games.
Intel Core i7: Socket 1366
Core i7 was previously the leader in quad core technology. Core i7 uses Intel Nehalem microarchitecture and is the successor to the Intel Core 2 series. However, Core i7 no longer has a Front Side Bus, or FSB. It now utilizes Quick Path Interlink also known as QPI. QPI is measured in gigabytes transferred per second (GB/s). Core i7 also implements an entirely new socket called LGA1366, which is incompatible with all earlier processors. Core i7 is a quad core which implements Intel’s Hyper-Threading technology, allowing for 8 processing streams. To support the speed and transfer rate of these processors all compatible motherboards utilize DDR3 memory.
Intel Core i7, i5: Socket 1156
The Core i7 and i5 for socket 1156 are the same as a Core i7 1366 processor except that the socket uses a few less pins and the processors lack a little performance next to the 1366 processors. However, the 1156 processors were more price effective for the average consumer to use. Many of the 1156 processors do not have the Hyper-Threading technology of the 1366 processors.
Intel Core 2 Quad
Core 2 Quad is based on the Kentsfield and Yorksfield microarchitecture, and was the most popular quad core on the market due to the price/performance of the CPU. Unlike Core i7, the Core 2 series still implements a Front Side Bus which ranges from 1066 MHz to 1600 MHz for the quad cores. The Core 2 Quad also has up to 12Mb of L2 cache. Core 2 Quad uses socket LGA775 also known as socket T. Socket T is the first processor socket to implement the contact pins for the CPU directly on the motherboard (opposed to having them on the processor, a trend AMD still continues) in an attempt to help reduce the chance of damaging or bending them. Core 2, unlike Core i7, does not use Hyper-Threading technology. So in that regard, you’re limited to 4 stream processes. Core 2 was the first series to introduce the 45nm die size.
Intel Core 2 Duo
The processors for Core 2 Duo series include the Conroe, Allendale, and Wolfdale microarchitectures. The Conroe and Allendale cores were the first Core 2 Duo cores, and have a 65nm architecture. The Wolfdale is the latest microarchitecture in the series, and had a shrink in die size to 45nm. Like the Core 2 Quad, the Core 2 Duo does not have Hyper-Threading technology and since it’s a dual core processor you’re limited to 2 stream processes. The Core 2 Duo, also like Core 2 Quad, uses a Front Side Bus which ranges from 800 MHz to 1333MHz and has a max of 6Mb of L2 cache. Also, like the Core 2 Quad, the Core 2 Duo uses the LGA775 socket.
Intel Pentium Dual Core
The Pentium Dual Core is a budget dual core with a very similar architecture to the Core 2 processors. The Pentium Dual Core, like the Core 2, is also based on the Allendale and Wolfdale microarchitectures. However, the Pentium series has 1Mb of L2 cache and a Front Side Bus maximum speed of 1066 MHz ( it can reach speeds as low as 533MHz. The Pentium Dual Core, like the Core 2 series, does not have Hyper-Threading and has only 2 stream processes. The Pentium series shares the same LGA775 socket as the core 2 series, also known as Socket T.
The Celeron is the lowest performance CPU that Intel produces. It ranges in both single and dual cores and has a Front Side Bus ranging from 266MHz to 800MHz. The Celeron offers a max L2 Cache of 512KB. The Celeron series is based off of the Conroe-L, Prescott, Cedar Mill, and Allendale microarchitectures. However, like Pentium and Core 2 series, it uses the LGA775 socket and does not have Hyper-Threading technology. The stream processes change between 1 and 2 depending on if you’re using a dual core or a single core Celeron.
The Xeon processors are non-consumer processors that are used in single or multi CPU servers, workstations, and embedded systems. The Xeons come in either a dual or quad core implementations and are based on the Conroe, Allendale, Wolfdale, Kentsfield, Yorkfield, Wolfdale DP, Bloomfield, Clovertown, Tigerton, Dunnington, Harpertown, and Nehalem-EP microarchitectures. That is to say, the Xeon processors are based off of both the Core 2 and Core i7 architectures. The Core 2 based models have a Front Side Bus ranging from 800MHz to 1600MHz. The Core i7 based models have a Quick Path Interlink rate of 4.8 GT/s to 6.4 GT/s. The Core 2 based Xeons do not implement Hyper-Threading technology. However, the Core i7 Xeons do implement Hyper-Threading technology. Xeon processors range between 2 to 8 stream processes. Xeon processors have 3 different sockets: Socket 771, Socket 775, and Socket 1366. Xeons based on the Core 2 architectures use socket 771 and socket 775, while Xeons based on the Core i7 architectures use Socket 1366.
AMD Phenom II
Phenom II is the latest CPU that AMD has released to the consumer market. Phenom II is made up of dual, triple and quad core processors (these include X2, X3 and X4). The Phenom II processors all contain 512KB L2 cache per core and contain between 4Mb and 6Mb of L3 cache. AMD’s processors use neither Front Side Bus nor Quick Path interlink. Instead, they use HyperTransport technology which rates the processors in MT/s, or megabytes transferred per second. All Phenom II processors have an HT speed of 4000MT/s. The Phenom II processors are based on the Callisto, Heka, and Deneb microarchitectures and utilize the Socket AM3 and Socket AM2+.
The Phenom has two different categories: X3 and X4. Phenom X3 is a triple core processor while Phenom X4 is a quad core processor. The Phenom X3 processors have an HT speed of 3600MT/s while the Phenom X4 can reach up to 4000MT/s. Both X3 and X4 processors have 512KB L2 cache per core, as well as 2Mb of L3 cache that is divided among the cores. The Phenom X3 cores are based on the Toliman microarchitecture and the Phenom X4 cores are based on the Agena microarchitecture, which implement Socket AM2 and Socket AM2+ respectively.
AMD Athlon II X2
Athlon II X2 is a class of processors that contain only dual core processors. Based off the Regor microarchitecture, the Athlon II X2 has an HT speed of 4000MHz. Like the Phenom II, it utilizes Socket AM3 as well as Socket AM2+. The Athlon II X2 has 2 x 1Mb of L2 cache. Unlike the Phenom series, the cache is not shared on this processor meaning each core gets 1MB. The Athlon II X2 cores range in speeds from 2.8GHz to 3.0GHz. This processor is geared for consumers who have a budget but wish to have some performance as well.
AMD Athlon X2
The Athlon X2 series contains the Athlon X2 and the Athlon 64 X2. Both processors are dual core CPU and have an HT speed of 2000MHz. The Athlon X2 series, like the Athlon II X2, has 1Mb of L2 cache per core. The Athlon 64 X2 is based on the Windsor and Brisbane microarchitecture while the Athlon X2 is based off the later Kuma microarchitecture. The Athlon 64 X2 and the Athlon X2 both use the Socket AM2. However, if you’re looking for something to upgrade in the future you want to look at a Socket AM3 processor. Socket AM2 is slowly becoming obsolete as manufactures have moved in the direction of DDR3 RAM support.
AMD Athlon 64
The Athlon 64 is a Socket AM2 single core processor meant for consumer use. These sets of processors have an HT speed of 2000MHz. The Athlon 64 processor has 512KB of L2 cache and 64KB of L1 data cache, as well as 64KB L1 instruction cache. The Athlon 64 processors are based on the Orleans and Lima microarchitectures.
The Sempron series, like the Athlon 64 series, is a single core Socket AM2 processor but is more geared for budget consumer use. The Sempron has an HT speed of 2000MHz and an L2 cache of 256KB. The Sempron is based on the Manila, Sparta, and Sargas micro architectures.
The Opteron series is a server series processor which comes in both four and six core designs. The Opteron series has processors for several sockets which are Socket F, Socket F+, Socket AM3, Socket AM2+ and Socket AM2. The Opteron cores are based on the Santa Rosa, Barcelona, Shanghai, Istanbul, Santa Ana, Budapest and Suzuka micro architectures. The quad core Opteron has an HT speed of 1000 MHz, a shared 8Mb of L3 cache, and 512KB of L2 cache per core. The six core Opteron has an HT speed range of 2.0 GT/s up to 4.8GT/s, and like the quad core has 8Mb of L3 cache to share and 512KB of L2 cache per core.
All processors AMD or Intel produce now have low wattage options. Most processors operate between 45 and 130 watts, sometimes even lower. Higher power consumption means you’ll need more watts from your power supply. So when choosing a CPU, remember to choose an adequate power supply. Also make sure to account for your video cards and drives.
Among all computer components, microprocessors are among those with the least return rates and thus the highest reliability, which is true for all brands of microprocessors. This is probably due to the fact that the microprocessors are mass-produced by machines with little if any, human interaction. In addition, the quality control process can be automated.
Price vs. Performance:
There is typically no good correlation between these two factors, especially at the top speeds. Average users should not purchase the top-speed on the market. The price difference is not worthy of the performance difference. So when trying to decide what is right for you figure out your budget then figure out your configuration, whether it is AMD or Intel, then decide which processor best fits your price range.
AMD vs. Intel
The battle between AMD and Intel has been ongoing since the first processors. Over time they have changed back and forth over which to buy. However, as of now if price is not important then Intel is the way to go. While Intel processors are more expensive you will receive more performance from Intel CPUs. The exception to this is when you look at the Celeron processors. AMD Sempron out performs the Celeron and is cheaper in price. Now if you’re looking to buy a CPU on a small budget then AMD is the way to go. AMD processors are all cheaper than Intel and provide adequate performance for their price. So in conclusion, while Intel's processors outperform AMD's processors in the high end if price is an object then AMD is for you, if price is no object and you want all out performance go with Intel.
When choosing a motherboard and CPU, if you are not going for top of the line try to get a motherboard that supports higher than the processor and memory you are going to choose. This way in the future when you decide you need a faster processor, or you just need more memory to run more programs, you will be able to add to the same motherboard instead of rebuilding the entire computer. Also, with minor changes you might not even have to reinstall your operating system since your motherboards chipset didn’t change.
Overclocking should not be attempted by novice computer users. Inputting the wrong data may cause CPU failure which is not covered under any warranty.
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