Intel in January stopped shipments of the Series 6 chipsets used with its much vaunted Sandy Bridge processors. The reason: a problem with the SATA controller that could over a period of time cause problems with SATA-linked devices.  PC Advisor explains what Intel's design flaw means for those who are about to buy an Intel Sandy Bridge PC, or have already taken the plunge. Updated, 16 February 2011.

Intel halted shipments of a key chipset used with the latest-generation Core i5/i7-series quad-core processors in late January.

The Series 6 chipsets are used with Sandy Bridge CPUs. The reason: a fault with the SATA controller that could cause long-term problems with SATA-linked devices such as hard disks and optical drives.

Specifically, the PC's motherboard that manufacturers such as Asus, Gigabyte and MSI have been providing to PC makers could suffer failure after prolonged use.

Intel has stopped shipment of the affected support chip, the platform controller hub (PCH), codenamed Cougar Point. The design issue has been fixed, Intel has said. But what exactly happened, and what can you expect if you've bought or are planning to buy a laptop or a desktop PC with a Sandy Bridge processor?

See also: Sandy Bridge mistake shows just how important Intel is

See also: Intel Core i7-2600K (Sandy Bridge) review

Intel Sandy Bridge: The problem

The Cougar Point chipset allows up to four SATA ports at the legacy 3 gigabits per second (Gbps) speed, and two with the higher-speed 6Gbps interface. The problem lies in the SATA 3Gbps interface.

Note: there is some confusion over the naming of different generations of SATA interface. At PC Advisor, we use the unambiguous convention based on communication rate speed: first generation of the SATA interface was specified at 1.5Gbps, and is sometimes called ‘SATA 1'. This was followed by SATA 3Gbps, or ‘SATA 2'. SATA 3 is really SATA 6Gbps.

According to industry sources, the interface that controls the movement of data – also known as the ‘clocking tree' – has been fitted with a transistor whose voltage was biased too high, resulting in a high level of leakage current. Leaking current could, in time, cause the SATA 3Gbps ports to fail. Intel maintains that this would not cause any damage or corruption to a connected hard disk, for instance, but we have heard predictions that 5 to 15 percent of systems could break down within three years.

It's a microscopic and massive error, but one that's relatively simple to fix in new products. So what about those products that have already shipped?

See also: Latest Components/Upgrades reviews

Intel Sandy Bridge: What happens now?

Many industry insiders expected that Intel would recall all the chipsets, and those people who already had Intel Sandy Bridge PCs would have to return them for repair.

As big a problem as that would be, the relatively few people who already have such laptops and desktop PCs pales into insignificance next to the real issue: the millions of motherboards already shipped or in transit to PC manufacturers.

One option open to PC suppliers is to supplement the sale of a new PC with a lengthy ‘no quibble' guarantee – possibly with financial support from Intel.

But PC makers are beholden to motherboard suppliers. Gigabyte, for instance, issued a Q&A unveiling its plans for the affected motherboards. In part it says: "No action will be needed if you use only the SATA 3 [sic] ports. If you are using the SATA 2 ports, then there are possibilities that the device's performance will decrease after a period of usage.

"To ensure the highest standard of customer support & services, Gigabyte recommends that all customers who purchased Gigabyte 6-series motherboards contact their local dealer (retail store where you purchased the motherboard) at the end of April for a motherboard exchange. Gigabyte will provide an equivalent new motherboard replacement."

Or to put it another way: the consumer needs to work out if they have an affected PC – and that means ascertaining whether they're using all the PC's capabilities, and whether they ever intend to – then take the motherboard back to the PC vendor to be swapped for a new one.

On the face of it this seems to be a disingenuous offer – as one PC Advisor staffer quipped: "It's not exactly like just pulling the tray out of the toaster to empty the crumbs out." A motherboard replacement is a delicate procedure that we wouldn't recommend to most users.

Asus, on the other hand, told PC Advisor that it intends to offer full refunds to any consumer who has purchased a PC with a faulty board it supplied. It said that it was calling a halt to all sales of potentially affected motherboards, and that customers should contact their PC vendor.

See also: Find out your consumer rights

Intel Sandy Bridge: Should you buy now?

Tests we've carried out in the PC Advisor Test Centre have established that Sandy Bridge is a considerable step forward in performance. However, with supplies of remedied motherboards in short supply until April, it may be time for pause for thought if you're considering buying a PC.

In a statement released 31 January, Intel said the "total cost to repair and replace affected materials and systems in the market is estimated to be $700m. Since this issue affected some of the chipset units shipped and produced in the fourth quarter of 2010, the company will take a charge against the cost of goods sold".

But this isn't clear enough in explaining to the end user who will fix their PC if it should break down due to a faulty chipset. We asked a selection of UK PC makers what their intentions are on this issue.

NEXT PAGE: what the UK PC makers say >>

Intel in January stopped shipments of the Series 6 chipsets used with its much vaunted Sandy Bridge processors. The reason: a problem with the SATA controller that could over a period of time cause problems with SATA-linked devices.  PC Advisor explains what Intel's design flaw means for those who are about to buy an Intel Sandy Bridge PC, or have already taken the plunge.

Intel Sandy Bridge: what UK PC makers say

We spoke to a selection of UK PC vendors, in order that they can explain their policies.

In the short term, do you plan to continue to sell Sandy Bridge PCs while waiting for revised motherboards with Cougar Point SATA chipsets?

Chillblast, CyberPower, Eclipse and Palicomp gave us a straight yes to this question, but told us they would be keeping their customers informed of the situation.

Arbico told us it hadn't sold any Sandy Bridge PCs prior to the recall, but will do so now having first informed customers of the issues, and installing an additional PCI-based SATA 3Gbps card to provide extra SATA ports and then circumnavigate, in principal, the problem.

DinoPC said it had removed existing Sandy Bridge PCs from sale, but is selling current review systems and informing customers of the situation at the point of sale.

If yes, will you replace these first-generation motherboards as a matter of course at no cost to the customer when new motherboards appear, or only if problems are reported later?

CyberPower, DinoPC and Palicomp told us they will replace motherboards at no cost to the customer as a matter of course if a fault is uncovered. Chillblast went further, saying it "will replace these motherboards if the need arises in the future in the event of the system SATA ports failing. If customers wish to exchange [non-faulty] boards when Cougar Point appears they can do so free of charge" - although customers will have to pay for pickup and return.

Arbico said it won't take back Sandy Bridge PCs to resolve this issue because of its bundled SATA card, and Eclipse said only that it was "happy to extend any courtesy exchange policies that motherboard manufacturers will follow".

For how long will the motherboard be covered by warranty, and what costs if any will be passed on to the customer for collection/shipping, parts and labour of the replacement?

All Asus motherboards are covered by a three-year swap-out warranty. DinoPC and Palicomp will cover the motherboards in their standard one-year warranties; Chillblast for two years.

CyberPower said: "We will be recalling all at our cost, so warranty does not really come into it," while Arbico is excluding this motherboard issue from its own warranties because of its inclusion of a substitute SATA PCI card. Eclipse responded that it will "try to get goodwill claims from the manufacturers where the customers are inconvenienced as little as possible".

Do you have other contingency plans in place, such as avoiding the use of SATA 3Gbps ports or including SATA PCI cards?

Chillblast and Palicomp said they will, where possible, limit the SATA 3Gbps controllers to optical drive-use only – hard drives will be connected to 6Gbps controllers, thus minimising the risk without unduly affecting performance.

Chillblast said further that it will offer SATA controller cards similar to Arbico's, at a "reduced price".

Arbico is adding a SATA card, while Eclipse will release systems that use only SATA ports 1 and 2 (6Gbps), removing the issue (but also not using the motherboards to their full potential). Similarly, DinoPC said it will connect devices to unaffected faster connections only and recommend to customers that they change to a motherboard that has four such connections if they have more than two SATA devices, or are planning to upgrade.

CyberPower also said it would put all connections on the unaffected SATA 6Gbps ports, but said it would add SATA PCI Express cards where required.