Phenom II Versus Core i7-920: Competing System Cost Analysis
With these potential issues in mind, how do we set up a fair comparison between similarly priced Phenom II and Core i7 systems?
To truly realize the cost difference, we need to list and price the PC components that are linked to either the Phenom II or Core i7 CPU.
For instance, the case, power supply, hard drives, optical drives, etc. are generic and can be used for any kind of CPU. The components that are specific to an AMD or Intel platform would be the CPU, motherboard, RAM, and CPU cooler.
Let's start with our Core i7 build. In this case, we will use the same one we set up for the last SBM:
| Core i7: Core System Components | ||
|---|---|---|
| Motherboard | DFI LANParty Jr X58-T3H6 Micro-ATX Intel X58/ICH10R, LGA1366 | $199.99 |
| Processor | Intel Core i7-920 Four Cores, 2.66 GHz, 8 MB Cache | $279.99 |
| Memory | G.Skill 10666CL7T 6GBPKTriple-channel memory kit, 3 x 2 GB | $94.99 |
| CPU Cooler | Xigmatek Dark Knight S1283 | $39.98 |
| Total Cost | $614.95 |
Why did we choose these parts for the i7 system? For starters, the Core i7-920, which retails for less than $300, is the cheapest Core i7 CPU by far. The next step up, the Core i7-940, costs about twice that for only a couple hundred more megahertz. Intel's Core i7-920 is also known to be a fantastic overclocker, so it's an easy choice.
The motherboard we chose is DFI's X58-T3H6 because we needed a MicroATX board to fit in our previous SBM system, but any quality X58-based motherboard--a requirement of the Core i7 CPU--will be in this price range. The cheapest Core i7 board we could find was the MSI X58 for $170, which is $30 cheaper than the DFI board we chose.
For RAM, we chose the most cost-effective module we could find with CAS 7 timings, G.Skill's PC3-10666. Because the Core i7 benefits from running in triple-channel mode, we needed a triple-channel kit to squeeze the most performance out of it. For under $100, the kit isn't a huge expense.
Finally, a good Core i7 build needs a solid cooler, and Xigmatek's Dark Knight will do the job for $40.
So, the base cost of our Core i7 build comes to about $615. Let's see how much a Phenom II build will run us:
| Phenom II: Core System Components | ||
|---|---|---|
| Motherboard | ASUS M4A79T Deluxe AMD 790FX, AM3 | $199.99 |
| Processor | Phenom II X4 955 Black Edition Four Cores, 3.2 GHz, 6 MB Cache | $245.00 |
| Memory | G.Skill 10666CL7T 6GBPKDual-channel memory kit, 2 x 2 GB | $64.99 |
| CPU Cooler | Zerotherm NV120 | $49.99 |
| Total Cost | $539.97 |
A little more thought went into the AMD system. Why didn't we go with a cheaper DDR2 motherboard, less expensive RAM, and a lower-end Phenom II processor? We'll tell you, but first we have to consider the price of the components we've chosen.
At $540, the Phenom II X4 955 system's core components cost about $75 less than the Core i7 system's core components. This represents the price difference between a pair of Radeon HD 4870 and Radeon HD 4890 cards. With this in mind, let's consider what we could've done differently.
First of all, the processor we chose was the Phenom II X4 955 Black Edition. There are a number of good Phenom II processors from which to choose, ranging from the cheaper AM2+ models that use DDR2 to the triple-core X3 models that can use either DDR2 or DDR3. These CPUs offer a low price and reasonable performance (especially for games, since many game engines tend not to use more than three CPU cores, anyway).
If that is the case, why did we go with the most expensive Phenom II CPU for this build? The decision hinged on this: what could we get with the extra cost savings? We already have enough money left over in our budget to upgrade from a pair of Radeon HD 4870s to two Radeon HD 4890 cards in the Phenom II system. If we go for a cheaper CPU, saving another $100 or even $200 doesn't allow us to upgrade to a more powerful graphics solution because the next step up is a pair of Radeon HD 4870 X2 cards. These would cost $400 more, which is impossible with our budget.
The rest of the components fall into place from there. The Asus M4A79T Deluxe motherboard is certainly not the cheapest model, but it does sport the 790FX chipset and dual full-speed PCIe x16 slots for the CrossFire graphics cards. Cheaper motherboards with the 790FX chipset can be found for as low as $135, such as the DFI LANParty DK 790FX-M2RS, which is about $45 less expensive than our test setup. Since the cheapest X58 motherboards are about $30 less expensive than the one we selected, we're still in the same range here.
The choice of RAM is a notable deviation from the Core i7 components as well. Consider that a Phenom II system requires paired modules to operate in dual-channel mode, while the Core i7 requires one more module for triple-channel mode. While two 2 GB sticks of DDR3 RAM will leave us 2 GB short in comparison to the Core i7 system, we know from experience and testing that the real-world difference between 4 GB and 6 GB is almost negligible in most situations. Additionally, the cost savings from less RAM allows us to allocate more cash toward the Phenom II-based system's graphics cards.
Finally, the CPU cooler. Zerotherm's NV 120 is a nice unit, but most CPU coolers worth their salt will be in the same price range, so insert your favorite flavor of cooler if you disagree with the model selected.
We did have some forum users mention that we might want to spec out an even cheaper AM2+ Phenom II system and use the savings toward a solid state drive (SSD) instead of a graphics upgrade, but we're not sure that would provide enough of a tangible performance benefit to offset losing the 790FX chipset and its dual PCIe x16 graphics slots, the faster Phenom II X4 955 processor, and the speedy DDR3 RAM. It's certainly an option, though, and if you're simply looking to build an even cheaper gaming system, the AM2+ Phenom IIs are a very good choice.
Now that we understand what we're building, let's have a final look at all of the components in our test systems.