SecProbe.io

July 2, 2014

Via E -mail
Jeffrey Smith
Chief Executive Officer
Starboard Value and Opportunity Master Fund Ltd .
830 Third Avenue, 3rd Floor
New York, NY 10022

 Re: Quantum Corporation
 Preliminary Proxy Statement on Schedule 14A
Filed June 23 , 2014  by Starboard Value LP, S tarboard Value and
Opportunity Master Fund Ltd., Starboard Value and Opportunity S LLC,
Starboard Value and Opportunity C LP, Starboard Value GP LLC,
Starboard Principal Co. LP, S tarboard Principal Co. GP LLC, S tarboard
Value R LP, S tarboard Value R GP LLC, J effrey C. Smith , Mark R.
Mitchell , Peter A. Feld, Philip Black, Christopher F. Crowell , Louis Dinardo ,
Dale L. Fuller  and E dward Terino
 File No. 001-13449

Dear Mr . Smith :

We have reviewed your filing  and have the following comments.  In some of our
comments, we may ask you to provide us with information so we may better understand your
disclosure.

Please respond to this letter by amending your filing, by  providing the requested
information, or by advising us when you will provide the requested response.  If you do not
believe our comments apply to your facts and circumstances or do not believe an amendment is
appropriate, please tell us why in your respon se.

After reviewing any amendment to your filing and the information you provide in
response to these comments, we may have additional comments.

General

1. Please fill in the blanks in your preliminary proxy statement.

2. Please disclose that stockholders w ho grant a proxy to the participants will be precluded
from exercising their full voting authority for the election of directors, given that the
participants are proposing only six nominees for seats on the board of directors.

Jeffrey Smith
Starboard Value and Opportunity Master Fund Ltd . et al.
July 2, 2014
Page 2

 Letter to Stockholders

3. Please disclose “the perspectives presented by Messrs. Black, DiNardo, and Smith in the
boardroom regarding ways to enhance stockholder value” and “the actions required to
maximize stockholder value.”

4. Please be advised that each statement or assertion of opinion or belief must be clearly
characterized as such, and a reasonable factual basis must exist for each such opinion or
belief.   Support for opinions or beliefs should be self -evident, disclosed in the proxy
statement, or provided to the staff on a supplemental basis.  W e note the following
statements:

 the disclosure on page 3 that you have little confidence that the board has the objectivity
and commitment to take the steps necessary to enha nce stockholder value; and

 the disclosure s on page 6 tha t the board “has not  taken sufficient action to improve
operations or hold management accountable ” and that the board “has not insisted on or
provided for increased accountability .”

In the future, please clearly characterize similar disclosure as beliefs or opinions and, as
necessary, disclose the bases for your opinions and beliefs.

5. We note your statement on page 6 that the company’s “EPS loss of 9 cents  . . . was far
short of the original guidance of earnings of 5-10 cents .”  Please clarify whether thes e
metrics are presented on a GAAP or non -GAAP basis.

We are Concerned with the Company’s Poor Performance, page 5

6. Please tell us how you calculated EBITDA, EBIT and EBITDA margins.  These figures
do not appear to be consistent with the reported figures of the registrant.

Proposal No. 1 :  Election of Directors

The Nominees, page 11

7. Please briefly describe the potential effects of a change of control in the event it is
determined that the election of your nominees would result in a change of control.

Form of Proxy

8. Please revise to include the proposal to ratify the 2012 long -term incentive plan and the
proposal to ratify an amendment to the employee stock purchase plan , or inform
stockholders that they will not be able to vote on these proposals if th ey grant you proxy
authority.

Jeffrey Smith
Starboard Value and Opportunity Master Fund Ltd . et al.
July 2, 2014
Page 3

 9. Please state the order of priority of nominees to which you will allocate votes, if known.
If not known at this time, describe how this determination will be made.   Please also
provide a means  for stock holders  to affirmative ly withhold authority to cumulate votes
with respect to one or more nominees.

 We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filings to be certain that the filings includes the information the Securities Ex change Act of
1934 and all applicable Exchange Act rules require.  Since the filing persons are in possession of
all facts relating to the disclosure, they are responsible for the accuracy and adequacy of the
disclosures they have made.

 In responding to our comments, please provide a written statement from each of the
participants acknowledging that:

 the participant is responsible for the adequacy and accuracy of the disclosure in the filing;
 staff comments or changes to disclosure in response to staf f comments do not foreclose
the Commission from taking any action with respect to the filing; and
 the participant may not assert staff comments as a defense in any proceeding initiated by
the Commission or any person under the federal securities laws of th e United States.
 If you have questions or comments please contact Jeff Kauten, Staff Attorney, at (202)
551-3447  or the undersigned at (202) 551 - 3457 .

        Sincerely,

        /s/ Maryse Mills -Apenteng

        Maryse Mills -Apenteng
        Special Counsel

cc: Via E -mail
 Andrew Freedman
 Olshan Frome Wolosky LLP