6月份当季，即苹果公司（Apple）的第三财季，Mac是少数销量没有达到预期的产品之一。分析人士原本预计销量为420万台，但苹果公司只卖出了395万台。

    本周二苹果将公布第四财季业绩，这种情况可能不会重演。

    所有人似乎都同意Mac是推动本来可能萎缩的个人电脑市场继续增长的少数电脑产品之一，特别是7月份苹果推出了全新一代MacBook Air和Mac mini以来更是如此，这两款都是最受欢迎的苹果产品之一。

    我们的业绩预测调查中排名居前的53位分析师中，除了两人——券商Sterne Agee的肖•吴和券商Janney的比尔•蔡，所有人都预测苹果将打破去年圣诞节季度创下的413.4万台Macs销量纪录。虽然Macs销量预测值最低有吴和蔡的410万台，最高有535万台（AAPL Independent Analysts的奈维•奈格拉尼给出的预测值），但机构分析师和独立分析师的预测值差距还算比较小，至少与他们对营业收入、每股收益、iPhone和iPad的预测值相比是如此。

    Mac销量预期均值方面，职业分析师们给出的是430万台，博主们给出的估值是470万台。所有53位分析师给出的平均预期略高于450万台，同比增长16%。华尔街预计增幅14%，其他预计21%。

    美国东部时间周二下午4点半左右随着苹果季度业绩发布，我们将看到谁的预测最准确。苹果拟定于当日下午5点的电话会议上与分析人士讨论这些数据，电话会议的网络直播可点击这里。

    下表是迄今为止我们收集的预测数据及其提交日期，独立分析师标绿，机构分析师标蓝。排名反映的是过去三个季度各分析师的营收和每股收益预测值的准确度(越靠后越准确)。

    The Mac was one of the few products that failed to live up to expectations in the June quarter (Apple's fiscal Q3). Analysts were looking for sales of 4.2 million. What Apple (AAPL) delivered was 3.95 million.

    That's not likely to happen again on Tuesday, when Apple reports its earnings for fiscal Q4.

    Everybody seems to agree that in a PC market that would otherwise be shrinking, the Mac is one of the few computer lines keeping it afloat, especially after the July refresh of two of Apple's most popular models: the MacBook Air and the Mac mini.

    Of 53 analysts polled in advance of our quarterly earnings smackdown, all but two -- Sterne Agee's Shaw Wu and Janney's Bill Choi -- are calling for Apple to beat the record 4.134 million Macs sold in the holiday quarter last year. Although the estimates range from Wu and Choi's low of 4.1 million to a high of 5.35 million (from Navin Nagrani of AAPL Independent Analysts), the spread between the institutional and independent analysts is relatively narrow, at least compared with their estimates for revenue, EPS, iPhones and iPads.

    The average Mac unit sales estimate among the pros is 4.3 million; among the bloggers it's 4.7 million. The average estimate of all 53 analysts is a little over 4.5 million, representing 16% growth from the same quarter last year. The Street is looking for 14%, the indies for 21%.

    We'll find out who was closest to the mark next Tuesday at about 4:30 p.m. EST, when the quarterly results hit the business wires. Apple is scheduled to discuss those results in a 5 p.m. conference call with analysts that the company will webcast here.

    Below: The estimates we've gathered so far and the dates they were submitted, with the independents in green and the institutionals in blue. The rank numbers show how accurate each analyst's revenue and EPS estimates were over the past three quarters (the lower the better).