Comparison between minicomputers and PC Linux Clusters

The investment in minicomputers is too expensive. I want to use several PC servers as Linux clusters. This saves a lot of investment and won't be inferior to minicomputers in terms of performance.
First of all, I raised this question to engineer Wang Xiaoqi of Zhejiang University quickway. He said that he did not do this in his company. At most, he did hot backup for two nodes. The reason is that the performance and stability of Linux Clusters cannot be compared with that of minicomputers. Obviously, this is not true. In terms of performance, p650 counts as 0.7 million. If you buy a PC, you can buy at least 20 bottom-end servers of the ibm x Series. If configured properly, the performance will not be worse than p650. In practice, 20 nodes are not required. As for stability, even if a single X Series server runs Linux, the service problem will not be very great. With the redundancy of so many nodes, the stability will not be a problem.

Then he found a simple engineer from IBM. Jian Gong seems to have agreed with him, but a key reason is that implementation is difficult, and it is rarely used in China. It is generally only used by scientific research institutions. Moreover, he said that IBM will not recommend immature products to customers, and application stability in key businesses is the first guarantee.
Now it seems that implementation difficulties have become the only problem. If such a cluster is successful, we believe it will play a significant role in promoting Linux applications in China. Ask other integrators. However, IBM does not do this. It is estimated that it is more difficult for other integrators.