Comparison of Core 2 Duo E8600 and Core 2 Quad Q9400 processors.
Comparison of Core 2 Duo E8600 and Core 2 Quad Q9400 processors.
I tried to upgrade my old machine to C2Q Q9400 but worry my PSU can't handle it—it’s not swappable. The comparison you linked shows only a 9% performance gap. That sounds about right. Since you need lower power usage, with 7.5A on the 12V rail and plans for a GPU, is that acceptable?
The Q9400 features four cores while the E8600 has just two. Don't rely on userbenchmark for comparison. Check out a YouTube video such as "Q9400 vs E8600 gaming" for a better view. Userbanchmark isn't very reliable. I’d definitely choose the Q9400 and even attempt to overclock it. The E8600 performs better on a single core, but the Q9400’s multi-core setup is a major advantage.
A quad-core processor would perform better than a dual-core one. Pairing it with an SSD would make your PC feel fast, almost as if you just purchased it yesterday.
Your power supply only handles 7.5A at 12V, which is 90 watts, but your components draw more than that. The GPUs seem to be drawing a lot of power—around 95W or higher. Online specs often show total system draw without knowing the CPU's actual consumption. Since the integrated GPU is struggling with low-res video, you might want to upgrade to a dual-core processor and a better GPU like the GT710 (19W) or a more powerful one if possible.
Core 2 processors lack built-in GPU; it resides on the motherboard. A separate GPU is required to stream 1080p videos. For 1080p use, a GT710 is recommended. If you need more power, opt for four cores. Core 2 Quads are available around $15.
Core2 Quad offers significantly greater strength compared to Core2 Duo. While having two cores provides a noticeable boost, the improvement is more evident when considering single-core speed—Core2 Duo runs at 3.33GHz while Core2 Quad hits 2.66GHz. Multi-core results are equally impressive, with Quad delivering 4x speed versus Duo’s 2x. This gap becomes clear when looking at real-world performance rather than just raw numbers. These figures are based on a benchmark using an I9 9900KS, so the modest rise between Core2 models makes sense. When focusing solely on the Core2 lineup, you’d see nearly double the gain from two to four cores. Keep in mind that these tests measure raw power output, not actual usage. You can check this comparison here: https://cpu.userbenchmark.com/Compare/In...1706vs2720
Regarding your power unit, what makes swapping difficult? Please share your specifications and some images of your setup. A quality PSU is crucial for optimal performance. For future upgrades, a strong GPU is highly recommended.
Personal advice: I own an LGA771 Xeon E5440 running on a GA-G41M-S2P with 8GB DDR3 RAM. The main component on my system is the HD7950 graphics card. I frequently play games like Ride 4, Battlefield, Far Cry Primal, and many intense titles at 60 FPS on full settings. GTA V runs smoothly at around 30 FPS online with a full server. I can also stream 1080p videos on YouTube while gaming. My rig outperforms my father’s, which uses a Ryzen 5 1400 with 16GB RAM and an RX560. If you’re considering upgrading, a Xeon CPU is ideal. If you stick with DDR2 memory, consider moving to a DDR3 motherboard with at least 8GB. A solid-state drive adds value even with high-end CPUs. A GT710 will help, but if you opt for a top-tier Core2 Quad, it’s a great choice.
If you’re on an I9 or Threadripper CPU, a GT710 can make a difference. However, if you choose DDR2 RAM, upgrading to DDR3 is advisable. A SSD also improves performance regardless of CPU type. The Q9400 model has a 65W TDP but draws 132.48W under load. My E5440 runs at 80W TDP and uses 108.5W continuously. The E8600 consumes 100.31W with the same TDP. The difference between these two is minimal, but you can find more details here: https://www.cpu-world.com/CPUs/Core_2/Intel-Core 2 Quad Q9400S AT80580AJ0676M
Your PSU’s 90W rating on the 12V rail might seem insufficient for running the Core2 Duo at peak settings. In practice, it falls short, especially when RGB lighting is active—adding that visual element can boost performance by up to 1000%.
The clock speed remains similar, offering 3.20GHz or more with the Q9400. For the Q9550, it provides double the cache and nearly double the transistors on the chip. The LGA775/1 has significant limitations in RAM speeds and capacity (8GB at 1333MHz is quite low), but increased cache should boost performance for both RAM and CPU. Regarding transistors, they generate heat and power usage remains similar, though they offer better stability and handle heavier workloads with improved efficiency. If your tower doesn’t support PSU swapping?
It's a one-of-a-kind PSU designed for a compact, mini workstation setup. Features a flexible, foldable layout and an unusual L-shaped configuration.