Early tests, online discussions and even some OEMs seem to show a potential bump in the road for Intel's latest-generation processor architecture a bump you can see on a temperature graph.

The new Haswell line of processors, at least according to early scuttlebutt from various quarters of the Internet, appears to generate more heat at a given voltage than the preceding Ivy Bridge-based designs, which creates problems for system builders.

[MORE HASWELL:Intel jumps into cloud gaming with first Haswell server chip]

A report from UK-based PCPro says that four British PC makers have complained anonymously that production-model Haswell chips have failed to reach the performance levels possible in pre-production samples, forcing them to scale back clock speeds in planned designs. One company told the publication that "40 or 50 retail chips had been impossible to overclock beyond 4.2GHz because of the high voltages and unsafe temperatures involved."

"Even at stock speeds, [retail chips] are running hotter than Ivy Bridge or Haswell samples," said another firm. (It should be noted that Intel does not guarantee overclocking performance or cover overclocked chips under warranty.)

Early test results from hardware sites have found much the same thing. Xbit Labs' test of the high-end Core i7-4770K found that "even a small increase in voltage leads to a dramatic increase in temperature of the computing cores, which means that the Haswell microarchitecture is energy efficient at low clock rates and low voltages only."

Xbit called the temperatures at an overclock of 4.4GHz "alarmingly high," despite the presence of a powerful after-market cooler. What's more, even without an overclock, the Core i7-4770K drew 30W more power under full load than the last-gen Core i7-3770K a substantial loss of energy efficiency.

Similar results were reported by PCPer, which also gave Haswell poor marks for power usage and cooling at the high end.

"I should be upfront here and just let everyone know the truth: Haswell doesn't overclock as well as [Sandy Bridge] or [Ivy Bridge] and it gets significantly hotter," that site said.

The well-regarded Tom's Hardware concurred: "We're going to have to accept that Haswell-based parts get hotter, faster, it sounds like, and that they might fall a few hundred megahertz short of comparable Ivy Bridge-based parts with conventional cooling methods," that site wrote.

Email Jon Gold at [email protected] and follow him on Twitter at @NWWJonGold.

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