Intel Core 2 Extreme QX9650 vs Intel Core i5-680 Comparison

The Verdict

The benchmark database positions the Intel Core i5-680 ahead of the Intel Core 2 Extreme QX9650 in every recorded head-to-head test. The i5-680 wins all five shared benchmarks, with margins ranging from 7.3% to 8.1%. The Core 2 Extreme QX9650 does not record a single win in the comparison set.

The i5-680 is the pick for anyone running Cinebench workloads, whether single-threaded or multi-threaded. Its advantage is consistent, not situational. The Core 2 Extreme QX9650 remains competitive in aggregate scoring, with an average benchmark score of 789 versus the i5-680’s 772, but that average draws from a broader test list that includes Geekbench results, which the i5-680 does not share in this database. In the tests where both chips appear, the i5-680 leads every time.

The Core 2 Extreme QX9650’s unlocked multiplier makes it the choice for users who intend to manually adjust clock speeds, since the i5-680’s multiplier is locked. The data does not quantify overclocking results, but the specification difference is clear. For stock operation, the i5-680 is the stronger performer across the recorded Cinebench suite.

Architecture Differences

The two processors come from different Intel eras. The Core i5-680 uses the Westmere architecture on the Clarkdale codename, built on a 32 nm process node. The Core 2 Extreme QX9650 uses the Core 2 architecture on the Yorkfield codename, built on a 45 nm process node. The i5-680 integrates 382 million transistors on an 81 mm² die, while the QX9650 packs 820 million transistors across two 107 mm² dies.

Core counts differ substantially. The i5-680 has 2 physical cores and 4 threads, relying on hyper-threading. The QX9650 has 4 physical cores and 4 threads, with no hyper-threading. Cache layouts are also distinct. The i5-680 provides 64 KB of L1 per core, 256 KB of L2 per core, and 4 MB of shared L3. The QX9650 provides 64 KB of L1 per core and 12 MB of shared L2, with no L3 cache at all.

Clock speeds favor the i5-680 in raw frequency. Its base clock is 3.60 GHz with a boost clock of 3.87 GHz. The QX9650 has a base clock of 3.00 GHz and no recorded boost clock. The i5-680 also draws far less power, with a TDP of 73 watts versus 130 watts for the QX9650.

Socket and memory support separate the platforms further. The i5-680 uses Intel Socket 1156 and supports DDR3 memory in dual-channel configuration, with a memory bandwidth of 21.3 GB/s. The QX9650 uses Intel Socket 775 and supports DDR1, DDR2, and DDR3, also in dual-channel configuration, but no memory bandwidth figure is recorded. The i5-680 includes integrated graphics (Intel HD), while the QX9650 relies on a chipset feature for graphics on certain motherboards. The i5-680 supports PCIe Gen 2 with 16 lanes from the CPU, while the QX9650 supports PCIe Gen 2 without a lane count specified.

Where Each One Wins

The data shows a clean split in benchmark outcomes: the i5-680 wins in every shared test, while the QX9650 has no wins in the head-to-head set. But the QX9650 does have a broader benchmark footprint. The database includes Geekbench multicore and singlecore scores for the QX9650, at 1443 and 509 respectively. Those tests are not recorded for the i5-680, so no direct comparison is possible there.

For Cinebench workloads, the i5-680 is the clear leader. Its smallest margin is 7.3% in Cinebench R20 single-core, and its largest is 8.1% in Cinebench R15 multi-core. The pattern holds across both single-threaded and multi-threaded rendering tasks. The i5-680’s higher clock speed and newer architecture appear to compensate for its 2-core deficit against the QX9650’s 4 physical cores.

The QX9650’s case rests on its unlocked multiplier. Users who prioritize manual frequency adjustment over stock performance would select it. The database does not record any overclocked results, so the potential gain is not quantified. In stock form, the QX9650 trails in every comparable Cinebench test.

The i5-680 also wins on efficiency. Its TDP of 73 watts is substantially lower than the QX9650’s 130 watts, which matters for system cooling and power delivery. The i5-680’s integrated graphics also remove the need for a separate GPU in basic display scenarios, though the QX9650 can use chipset-based graphics on certain motherboards.

FAQ

Q: Which processor has more physical cores?

A: The Intel Core 2 Extreme QX9650 has 4 physical cores, while the Intel Core i5-680 has 2 physical cores. The i5-680 compensates with hyper-threading, giving it 4 threads, matching the QX9650’s 4 threads.

Q: What is the performance difference in multi-core Cinebench tests?

A: The i5-680 leads in all recorded multi-core Cinebench tests. In Cinebench R15 multi-core, the i5-680 scores 226 versus the QX9650’s 209, an 8.1% advantage. In Cinebench R20 multi-core, the scores are 942 versus 872, an 8% advantage. In Cinebench R23 multi-core, the scores are 2243 versus 2077, also an 8% advantage.

Q: Does the Core 2 Extreme QX9650 have any benchmark wins?

A: No. In the head-to-head benchmark set, the QX9650 records 0 wins, while the i5-680 records 5 wins. The QX9650 does have Geekbench scores in the database, but the i5-680 has no Geekbench results for comparison.

Q: Which processor supports overclocking?

A: The Core 2 Extreme QX9650 has an unlocked multiplier, meaning the user can adjust frequency multipliers. The Core i5-680 has a locked multiplier, so it does not support the same level of manual clock adjustment.

Q: How do their power requirements differ?

A: The Core i5-680 has a TDP of 73 watts, while the Core 2 Extreme QX9650 has a TDP of 130 watts. The i5-680 draws significantly less power under load.

Q: What is the single-core performance difference?

A: The i5-680 wins in both recorded single-core Cinebench tests. In Cinebench R20 single-core, it scores 132 versus 123, a 7.3% advantage. In Cinebench R23 single-core, it scores 316 versus 293, a 7.8% advantage.

Head-to-Head Benchmarks

The recorded head-to-head data covers five Cinebench tests, and the i5-680 wins all of them. The narrowest margin appears in Cinebench R20 single-core, where the i5-680 scores 132 against the QX9650’s 123, a delta of 7.3%. The widest margin appears in Cinebench R15 multi-core, where the i5-680 scores 226 against 209, a delta of 8.1%.

The multi-core tests show a consistent pattern. In Cinebench R20 multi-core, the i5-680 scores 942 versus 872, an 8% delta. In Cinebench R23 multi-core, the i5-680 scores 2243 versus 2077, also an 8% delta. The i5-680’s 2-core, 4-thread configuration with a 3.60 GHz base clock and 3.87 GHz boost clock outperforms the QX9650’s 4-core, 4-thread configuration at 3.00 GHz in every rendering workload.

Single-core results follow the same direction. In Cinebench R23 single-core, the i5-680 scores 316 versus 293, a 7.8% delta. The i5-680’s clock speed advantage appears to drive these gains, as the QX9650 has no boost clock recorded and runs at a lower base frequency.

The aggregate benchmark averages tell a more nuanced story. The i5-680 has an average benchmark score of 772, while the QX9650 has an average of 789. The QX9650’s average is higher because its benchmark list includes Geekbench scores, which are not recorded for the i5-680. The nearest rivals for the i5-680 include the Intel Core i7-3687U at 773 (delta -0.1%), the Intel Celeron G5920 at 775 (delta -0.4%), the Intel Core i3-3250T at 775 (delta -0.4%), and the Intel Pentium Silver J5005 at 776 (delta -0.5%). The QX9650’s nearest rivals include the AMD Opteron 3350 HE at 789 (delta 0%), the Intel Core 2 Extreme QX9770 at 790 (delta -0.1%), the Intel Core i5-4210U at 788 (delta 0.1%), and the Intel Core i5-3610ME at 788 (delta 0.2%).

Both processors sit at the 21st percentile among all CPUs in the database. The i5-680’s percentile is 21, and the QX9650’s percentile is also 21. This places both chips in the same overall performance tier, despite the i5-680’s consistent wins in the shared Cinebench tests.

Specification Differences

The two processors differ in almost every major specification category. Core count: the i5-680 has 2 cores, the QX9650 has 4. Thread count: both have 4 threads, but the i5-680 achieves this with hyper-threading, while the QX9650 uses purely physical cores.

Clock speeds: the i5-680 has a base clock of 3.60 GHz and a boost clock of 3.87 GHz. The QX9650 has a base clock of 3.00 GHz and no recorded boost clock.

Power: the i5-680 has a TDP of 73 watts, the QX9650 has a TDP of 130 watts.

Socket: the i5-680 uses Intel Socket 1156, the QX9650 uses Intel Socket 775.

Architecture and process: the i5-680 uses Westmere on a 32 nm node with 382 million transistors on an 81 mm² die. The QX9650 uses Core 2 on a 45 nm node with 820 million transistors across two 107 mm² dies.

Cache: the i5-680 has 64 KB L1 per core, 256 KB L2 per core, and 4 MB shared L3. The QX9650 has 64 KB L1 per core and 12 MB shared L2, with no L3.

Memory: the i5-680 supports DDR3 in dual-channel configuration with 21.3 GB/s bandwidth. The QX9650 supports DDR1, DDR2, and DDR3 in dual-channel configuration, with no bandwidth figure recorded.

Graphics and PCIe: the i5-680 includes Intel HD integrated graphics and PCIe Gen 2 with 16 CPU lanes. The QX9650 has chipset-dependent graphics on certain motherboards and PCIe Gen 2 without a lane count specified.

Other differences: the i5-680 has a locked multiplier, the QX9650 has an unlocked multiplier. The i5-680’s part number is SLBTM, the QX9650’s is SLAN3. The i5-680 was released later, and its launch MSRP is $294. The QX9650 has no recorded launch MSRP. Both processors are end-of-life and target the desktop market segment. Neither supports ECC memory.