Laptops with Intel's new Core i3, i5 and i7 processors have started shipping to consumers, and include features that bring longer battery life and new levels of graphics and application performance to PCs.Many performance improvements are enabled by Intel's latest chips, which integrate a graphics processor and CPU in a single chip. The laptops also preserve battery life through chip-level improvements and technologies such as solid-state drives (SSDs), which draw less power than hard drives.Intel started shipping Sandy Bridge processors for laptops in late February, and laptops are slowly trickling out to replace models with older Intel chips. PC makers including Lenovo, Dell, Hewlett-Packard and Toshiba have already announced laptops based on new Core i3, i5 and i7 processors, with prices starting at US$599. I was awaiting the release of Sandy Bridge laptops to upgrade my aging Fujitsu LifeBook P8010, which I bought in mid-2008 for a bargain price of $710 off the PC maker's eBay auction store. The LifeBook was powered by the same dual-core Core 2 Duo microprocessor included in the original MacBook Air, and was made using the older 65-nanometer manufacturing process. Intel's latest Core chips are made using the latest 32-nm process, which has improved chip performance while reducing leakage, bringing longer battery life to laptops. The results were visible in a preproduction unit of Lenovo's upcoming ThinkPad X220 ultraportable laptop, which was loaned by the company for evaluation. The laptop's mundane black-box design was reminiscent of old ThinkPad models, but the machine showed significant graphics, performance and battery-life improvements compared to laptops based on older Intel chips.Lenovo says the X220 can clock 23 hours of battery life with a nine-cell battery and a spare external battery pack. Power consumption depends on laptop configuration, and the X220's runtime measured anywhere between seven and eight-and-a-half hours on a six-cell battery with a dimly lit screen. That compares favorably to five to six hours of battery life on my trusty old Fujitsu P8010, with a screen even dimmer. Dell and Toshiba have also touted long battery life as one of the major improvements with their new Sandy Bridge laptops. Dell's Inspiron 15R laptop, which includes a 15-inch screen, provides about 13 hours of battery life with a nine-cell battery. Toshiba said its Tecra R840 laptop, which includes a 14-inch screen, could deliver battery life of up to 11 hours when configured with an SSD. Some chip-level improvements have also helped improve battery life. Intel for the first time has roped in the graphics processor and CPU on one chip, and one way for chip makers to improve battery life is by pulling in more components inside a single chip. The laptop also consumed less power in sleep mode and did a better job at idling components than my three-year-old Fujitsu. Battery improvements also come with Intel's TurboBoost 2.0 technology, where idle cores can be powered down to preserve battery life. The feature is also designed to deliver better performance, and certain cores can be clocked up depending on the need for speed. The X220 laptop's performance improvements were evident in the quick Windows 7 boot time, which took 20 to 30 seconds. Mundane tasks such as antivirus did not affect the speed of other Windows applications or video running simultaneously. Intel's integrated graphics processor in the dual-core Core i5 chip was also able to handle full high-definition graphics, which is an improvement compared to Intel's previous generation of 32-nm Core processors based on the Westmere architecture, which were released last year. The X220 came with a 12.5-inch IPS display and delivered vibrant colors without high-definition images stuttering. The old LifeBook at best could handle standard-definition video, and some laptops from last year based on the Westmere Core i3 processors often stuttered when playing full 1080p video with applications running in the background. Intel has highlighted some additional graphics features on select laptops available through its latest Core processors, such as Quick Sync to quickly convert high-definition video into a format suitable for smartphones, and Wireless Display (Wi-Di) to wirelessly stream high-definition content from laptops to TVs.With Sandy Bridge, Intel's core strength is the CPU, but it has also come a long way in delivering better graphics, which shows in the X220. Intel's graphics processors are good for viewing Blu-ray video and for casual gaming, but for intense gaming, users would perhaps need to buy a laptop with a separate GPU.But on graphics Intel still lags competitor Advanced Micro Devices, which earlier this year released processors from the Fusion family, which also integrate a CPU and graphics processor on a single chip. Fusion chips integrate support for Microsoft's DirectX 11, which is a collection of APIs (application programming interfaces) to deliver more realistic images in Windows 7. Sandy Bridge chips integrate an older version of DirectX, and will catch up on DirectX 11 only next year.Based on the improvements in Sandy Bridge, I'm tempted to upgrade my aging laptop, which now has a half-cracked screen panel. But it is even more tempting to hang on a little longer to upgrade to laptops with Core processors due next year, which will be based on Intel's latest Ivy Bridge microarchitecture. Ivy Bridge chips will be made using the 22-nm manufacturing process, which could bring more battery life and performance to laptops. Ivy Bridge laptops will have DirectX 11 support and integrate interconnect technologies such as USB 3.0 and Thunderbolt, which could help transfer HD videos from laptops to external storage devices in a matter of seconds.As tempting as it may be, there is little reason to wait to upgrade laptops, said Dean McCarron, principal analyst at Mercury Research. Chips keep improving in performance, and battery life in laptops will just keep getting better, so people should upgrade laptops when necessary, McCarron said.I also had a fleeting thought on whether to ditch the laptop and switch over to a tablet. But I need a laptop for the keyboard and to run specific applications that may not run on tablets.The X220 will become available this month starting at about US$899, Lenovo has said.