<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-09-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000899297</issuerCik>
        <issuerName>OPTI INC</issuerName>
        <issuerTradingSymbol>OPTI.OB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001138996</rptOwnerCik>
            <rptOwnerName>S. MUOIO &amp; CO. LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>509 MADISON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 406</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001259267</rptOwnerCik>
            <rptOwnerName>SALVATORE MUOIO</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O S. MUOIO &amp; CO. LLC</rptOwnerStreet1>
            <rptOwnerStreet2>509 MADISON AVENUE, SUITE 406</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001173632</rptOwnerCik>
            <rptOwnerName>SM Investors II, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O S. MUOIO &amp; CO. LLC</rptOwnerStreet1>
            <rptOwnerStreet2>509 MADISON AVENUE, SUITE 406</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2013-09-12</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>.53</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3496278</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5995478</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2013-09-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2279</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>.53</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3498557</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5997757</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These securities are held in the accounts of several investment partnerships, investment funds and other accounts (collectively, the &quot;Investment Accounts&quot;) for which S. Muoio &amp; Co. LLC (&quot;SMC&quot;) serves as either general partner or investment manager. Salvatore Muoio is the managing member of SMC. SMC and Mr. Muoio may be deemed to beneficially own the securities held by the Investment Accounts by virtue of SMC's position as general partner or investment manager of the Investment Accounts and Mr. Muoio's status as the managing member of SMC.</footnote>
        <footnote id="F2">These securities are owned by SM Investors II, L.P. (&quot;SM Investors II&quot;), which is a reporting person. SMC serves as the general partner of SM Investors II. Salvatore Muoio is the managing member of SMC. SMC and Mr. Muoio may be deemed to beneficially own the securities held by SM Investors II by virtue of SMC's position as general partner of SM Investors II and Mr. Muoio's status as the managing member of SMC.</footnote>
    </footnotes>

    <remarks>+ Each of the Reporting Persons and the joint filers (individually, each a &quot;Reporting Person&quot; and collectively, the &quot;Reporting Persons&quot;) disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. The Reporting Persons affirmatively disclaim being a &quot;group&quot; for purposes of Section 16 of the Securities Exchange Act of 1934, as amended.</remarks>

    <ownerSignature>
        <signatureName>S. Muoio &amp; Co. LLC (+), By: /s/ Salvatore Muoio, Managing Member</signatureName>
        <signatureDate>2013-09-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Salvatore Muoio (+)</signatureName>
        <signatureDate>2013-09-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SM Investors II, L.P., By: S. Muoio &amp; Co. LLC, its general partner, By: /s/ Salvatore Muoio, Managing Member</signatureName>
        <signatureDate>2013-09-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
