CPU and GPU Performance
Cinebench is a familiar test in our benchmark suite and is used to examine the multi-core capabilities of each laptop's processor. The results are interesting, as while both PC Specialist systems are equipped with a 47W Core i7-4700MQ chip, it's the Optimus V that is able to realise the processor's full potential.
The SkyFire III is off the pace as a result of CPU throttling and delivers a benchmark score that's practically on par with the XMG P303 Pro, a 13.3in laptop armed with a slower 37W Core i7-4702MQ. PC Specialist has opted for what's technically the higher-performance processor, but given the thermal limitations, the Core i7-4702MQ may have been a better fit for the SkyFire III.
PCMark 7 is used to benchmark overall system performance, and it's a test that can be heavily influenced by ultra-fast SSDs. With a 120GB Kingston V300 at the helm, the Optimus V scores a reasonable 5,386 PCMarks. The SkyFire III, armed with a hybrid Seagate SSHD, slots in at 4,471. Neither system pushes the boundaries, but both feel quick during everyday use, with Windows 8 feeling responsive and loading in a matter of seconds.
On the GPU front, the SkyFire III and Optimus V are equipped with a GeForce GTX 760M and GeForce GTX 765M, respectively. How big a difference is there between the two?
Nvidia GeForce GTX Mobile Range |
||||
|---|---|---|---|---|
| Model | GeForce GTX 760M |
GeForce GTX 765M |
GeForce GTX 770M |
GeForce GTX 780M |
| Release Date | May 2013 |
May 2013 |
May 2013 |
May 2013 |
| Process | 28 |
28 |
28nm |
28nm |
| Architecture | Kepler |
Kepler |
Kepler |
Kepler |
| Processors | 768 |
768 |
960 |
1,536 |
| Texture Units | 64 |
64 |
80 |
128 |
| ROP Units | 16 |
16 |
24 |
32 |
| Memory Size | 2,048MB |
2,048MB |
3,072MB |
4,096MB |
| Memory Type | GDDR5 |
GDDR5 |
GDDR5 |
GDDR5 |
| Core Clock | 657MHz |
850MHz |
811MHz |
823MHz |
| Turbo Boost | GPU Boost 2.0 |
GPU Boost 2.0 |
GPU Boost 2.0 |
GPU Boost 2.0 |
| Memory Clock | 4,000MHz |
4,000MHz |
4,000MHz |
5,000MHz |
| Memory Interface | 128-bit |
128-bit |
192-bit |
256-bit |
| Memory Bandwidth | 64GB/s |
64GB/s |
96GB/s |
160GB/s |
Breaking out the specification table reveals that both GPUs have a lot in common. They are, for all intents and purposes, the same chip clocked at different base frequencies. The GTX 760M is dialled-in at a tentative 657MHz, while the GTX 765M is able to run along at 850MHz.
Putting the specification into perspective, the synthetic 3DMark 11 benchmark suggests that the SkyFire III's slower-clocked GTX 760M GPU loses roughly 15 per cent of the performance of the Optimus V's GTX 765M. The numbers are right where we'd expect them to be, but of course the SkyFire III does have one advantage; the GPU only needs to push 1.4 million pixels on the 14in display.
