Intel Core i5-760 in Detail
The Core i5-760 doesn't differ much from its predecessor Core i5-750. In fact, we can only see a small growth in clock rate. It is higher by 133 MHz, so the new model has a default clock rate of 2.8 GHz. Otherwise, it is the same quad-core Lynnfield which does not belong with the Core i7 family only because it lacks Hyper-Threading technology.
The following table sums up the Core i5-760 specs:
The Core i5-750 having been the junior quad-core LGA1156 processor, Intel did not need a new core stepping to produce the new model with a slightly higher clock rate. The i5-760 is based on a stepping B1 core, just like Lynnfield processors released a year ago. You can easily see it, for example, in this CPU-Z screenshot.
Despite the old stepping, we can see that the CPU voltage is rather low. Indeed, although the top default voltage for the Core i5-760 is 1.4 volts (the same as for the Core i5-750), the new processor actually works at much lower voltages.
Comparing the Core i5-750 with the new model, we can also note that the latter has more aggressive Turbo Boost technology. The Core i5-750 could increase its frequency multiplier by 4 under low loads, reaching a clock rate of 3.2 GHz whereas the Core i5-760 can increase it by 5 and reach a clock rate of 3.46 GHz. The frequency multipliers available for the Core i5-760 with Turbo Boost are listed in the following table:
Thus, the Core i5-760 looks more like a top-end CPU than the Core i7-860 in terms of its frequencies in default and Turbo modes.
Considering the increased default clock rate and the more aggressive Turbo mode, we can even view the Core i5-760 as virtually identical to the higher-class Core i7-860 with Hyper-Threading turned off but we should not forget that, besides the lack of Hyper-Threading, quad-core Core i5 processors differ from their senior cousins in one thing more: they have fewer memory frequency multipliers. As a result, the Core i5-760 can only support DDR3-1067 and DDR3-1333 unless you increase the base clock rate. The Core i7 series additionally supports DDR3-1600.
Testbed and Methods
The Core i5-760 is targeted at the mainstream market and priced accordingly. Intel seems to pit it against the six-core Phenom II X6 1055T, so we will compare these two CPUs in the first place. Besides, we will pinpoint the exact position of the new CPU among Intel's products by including similarly priced processors from the Core i7, Core i5 and Core 2 Quad series into this test session. Here is the full list of components we used:
- AMD Phenom II X6 1055T (Thuban, 6 cores/6 threads, 2.8 GHz, 6 MB L3)
- Intel Core i5-860 (Lynnfield, 4 cores/8 threads, 2.8 GHz, 8 MB L3)
- Intel Core i5-760 (Lynnfield, 4 cores/4 threads, 2.8 GHz, 8 MB L3)
- Intel Core i5-750 (Lynnfield, 4 cores/4 threads, 2.66 GHz, 8 MB L3)
- Intel Core i5-660 (Clarkdale, 2 cores/4 threads, 3.33 GHz, 4 MB L3)
- Intel Core 2 Quad Q9500 (Yorkfield, 4 cores/4 threads, 2.83 GHz, 6 MB L2)
- CPU cooler: Thermalright Ultra-120 eXtreme with an Enermax Everest fan
- ASUS Crosshair IV Formula (Socket AM3, AMD 890FX + SB850, DDR3 SDRAM)
- ASUS P7P55D Premium (LGA1156, Intel P55 Express)
- ASUS P5Q3 (LGA775, Intel P45 Express, DDR3 SDRAM)
- System memory: 2 x 2 GB DDR3-1600 SDRAM, 9-9-9-24 (Kingston KHX1600C8D3K2/4GX)
- Graphics card: ATI Radeon HD 5870
- Disk subsystem: Kingston SNV425-S2/128GB
- Power supply: Tagan TG880-U33II (880 W)
- Operating system: Microsoft Windows 7 Ultimate x64
- Intel Chipset Driver 184.108.40.2065
- ATI Catalyst 10.7 Display Driver
The Core i5-760 and Core i5-750 processors do not support DDR3-1600. Therefore we tested them with DDR3-1333 at 9-9-9-27 timings. The same is true for the LGA775 platform with the Core 2 Quad Q9500 processor.